EGU General Assembly 2023  

How to cite: Lichtenberg, T.: Tectonics and magma oceanography of rocky exoplanets, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1707, https://doi.org/10.5194/egusphere-egu23-1707, 2023.

A planet which is warm enough so that it lies above the gas/liquid critical point and above the solidification line of its main constituent is a fluid planet. This is the case of Jupiter and Saturn, and of all planets in the Universe that are dominated by hydrogen, due to its very cold critical point (33K) and low melting temperature. Planets mainly made of other elements than hydrogen and helium, such as water, may also be fluid, if they are close enough to their star. Hydrogen, helium and oxygen being the most abundant elements in the Universe, fluid planets hold some of the keys to understand our origins.

Being fluid implies that these planets have low viscosities and few barriers to convection and mixing. They are governed by the same hydrostatic equations as stars. The progressive transition between the gaseous atmosphere and the fluid interior allows one, in principle, to infer bulk composition from the atmospheric one. Behind their apparent simplicity, complications arise rapidly: How do these planets rotate? How efficiently would they mix other elements, particularly in the presence of condensation and clouds, but also when this is energetically unfavored? What is the effect of intense irradiation on the global heat transfer? 

Over the past 30 years, solutions or partial solutions to these questions have been provided thanks to a combination of theoretical studies and observations. Simple theories of the evolution and atmospheric properties of exoplanets have proven relatively successful. Advances in gravitational sounding of Jupiter and Saturn have provided the basis to understand and predict how fluid planets rotate. Constraints on the structure of the planets and on the presence of primordial dilute cores have been provided.  

Yet, recently, thanks to the Juno and Cassini observations, evidence of imperfect mixing and stable regions have arisen both in the deep atmosphere and interior of Jupiter and Saturn. Observed latitudinal and temporal variability in composition, lightning or general atmospheric properties have remained unaccounted for. Modeling atmospheric properties of fluid planets based on Earth parameterizations, not fully accounting for their abyssal nature and moist convection inhibition has failed. Fluid planets are more complex and challenging than previously envisioned. 

Progress will come from the continuation of a combination of studies: theoretical and numerical studies to understand heat transfer and mixing in the presence of condensation, observations of a large variety of exoplanets and measurements in solar system fluid planets. But the next milestone lies in the outer solar system, with the exploration of Uranus and Neptune. These planets are only partially fluid and may have a solid interior. This increased complexity matches what is to be expected for other planets in the Universe. Their atmospheres, made of hydrogen and helium and large amounts of methane, are laboratories to test models of heat and element transport in abyssal hydrogen atmospheres. An international mission with an orbiter and a probe would allow for the direct measurements that we need in order to interpret with confidence the great wealth of data awaiting us with the more distant exoplanets. 

How to cite: Guillot, T.: Fluid Planets: from Theory to Observations and Beyond, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8554, https://doi.org/10.5194/egusphere-egu23-8554, 2023.

The contemporary surface of Mars is shaped by wind driven sand transport, yet our knowledge of these processes is limited. Sand ripples are small bedform features commonly found superimposing dunes on the surface of Earth and Mars, perpendicular to the local wind direction. The mechanism behind the formation of Mars’ ripples is currently highly debated: either they are formed by saltation like Earth’s aeolian impact ripples, or they are formed by hydrodynamic instability such as subaqueous ripples. Investigating ripple pattern dynamics across the surface of Mars would improve our knowledge of local wind regimes and sand transport conditions, such as whether the dune shape and size affect wind flow, thus ripple patterns.

To enable efficient surveying of large areas of the surface of Mars, an automated mapping method has been developed to identify and categorise different classes of ripple patterns. For this project, ripple patterns found on barchan dunes across 40 HiRISE sites in the north polar region of Mars have been classified and segmented. The same mapping method will be applied to Earth’s aeolian impact ripples and subaqueous ripples to compare their morphology and dynamics with those on Mars. By doing so, we hope to determine the mechanism behind the formation of Martian ripples and more broadly enhance our understanding of sand transport conditions on the red planet.

How to cite: Delobel, L., Baas, A., and Moffat, D.: Analysis of Dune Ripple Patterns on the Surface of Earth and Mars to determine Local Sand Transport Conditions: A Machine Learning application., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-392, https://doi.org/10.5194/egusphere-egu23-392, 2023.

The Taurus-Littrow Valley, location of the Apollo 17 landing site, hosts recent, late-Copernican geomorphological landforms and tectonic structures, namely the Light Mantle avalanche deposit and the Lee-Lincoln lobate scarp. The Light Mantle deposit represents a unique case of a hypermobile avalanche on the Moon (El-Baz 1972; Schmitt et al. 2017). The Lee-Lincoln lobate scarp is the surface expression of a recent thrust fault (Watters et al. 2010), which is considered to be the source of strong seismic shaking throughout Taurus-Littrow Valley (van der Bogert et al. 2012, 2019), and potentially still active (Watters et al. 2019).

The Light Mantle represents the only extraterrestrial landslide for which an absolute age is provided (70-110 Ma), thanks to the Apollo 17 returned samples (e.g., Schmitt et al. 2017). Therefore, the Light Mantle deposit can be used as a geomorphological marker and time constraint for surface changes that occurred since its emplacement. By applying the principle of superposition, surface changes superposed on the Light Mantle deposit, and on the slope from which it was generated (the NE-facing slope of the South Massif), must post-date the landslide event. For example, small scale grabens (10-20 m wide) associated with the Lee-Lincoln lobate scarp are found superposed on the Light Mantle unit (Watters et al. 2010). These troughs likely formed less than 50 Ma and are thought to be generated by the flexural bending of the hanging wall (Watters et al. 2010, 2012). Similarly, boulder tracks, whose survival time is estimated to range up to 35 Ma (e.g., Arvidson et al. 1976; Kumar et al. 2019), are found on the NE-facing slope of the South Massif, therefore evidence that boulder falls have occurred after the Light Mantle landslide event.

Here, we extend the body of evidence of surface changes that have affected the South Massif since the emplacement of the Light Mantle deposit. We map boulder tracks, areas of disturbed regolith, linear slope structures, and other structures associated with the summit of the South Massif. We identified features (i.e., slope structures oblique to contours, the Nansen Moat and the trough at the NE-base of the Sout Massif) directly related to back-thrust faults associated with the Lee-Lincoln thrust fault, which are re-activating the buried fault that bounds Taurus-Littrow Valley; we identified other features (i.e., crestal graben-like structures, slope structures parallel to contours) that derived from gravitational adjustment following basal slope support removal due to back-thrust faulting. Moreover, the overlapping relationships between the boulder tracks and regolith disturbance suggests that continuous slope deformation has been affecting the NE-facing slope. We attribute the efficiency of the process to repeated ground-shaking perturbation, which maintains the slope in a perpetually unstable state.

We conclude that the NE-facing slope of the South Massif has been recently and continuously affected by slope deformation processes. We suggest that the efficiency of these processes is the product of lasting, and perhaps ongoing, effects of activity of the Lee-Lincoln thrust fault, coupled with the influence of the subsurface geometry of the valley inherited from the impact basin formation.

How to cite: Magnarini, G., Grindrod, P., and Mitchell, T.: Slope Deformation Associated with Recent Tectonism and the Lasting Effect of Local Subsurface Geometry in the Taurus-Littrow Valley, Apollo 17 Landing Site., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1320, https://doi.org/10.5194/egusphere-egu23-1320, 2023.

On planetary bodies, impact craters and fluvial activity interact, and valley incision competes with the topographic, lithologic and structural disruption caused by impacts that frequently occurred in the geologic past. Yet, many terrestrial and martian impact craters were breached by inlet valleys, which supplied (or still supply on Earth) crater interiors with water. Radial and concentric drainage patterns are also observed around craters, suggesting impact-induced structure fundamentally influences incision in these areas.

To gain a greater understanding of fluvial erosion in crater-dominated terrains, and inlet valley formation across crater rims, we will investigate the incision history of the Dhar valley inlet at Lonar Crater, Maharashtra, India. Lonar crater is the best-preserved impact crater in basalt, which formed within the last 100 ka when a bolide impacted the Deccan Traps basalts. At 1.8 km diameter and 135 m deep, it is a simple crater. A small, 5.5 m deep lake resides in the crater interior and is fed by the Dhar inlet to the north east, and groundwater springs in the crater walls. We would use cosmogenic radionuclide dating to investigate the onset and timescales of fluvial erosion that formed the inlet valley, with comparison to the surrounding non-cratered terrains. We plan to measure the accumulation of cosmogenic ³He in pyroxene and olivine to derive in situ exposure ages at different levels in the valley, and also to derive basin-averaged denudation rates from fluvial sediments. Vesicle-fill quartz is also present, so measurement of cosmogenic ¹⁰Be is a possible complement to ³He measurements.

We also plan to complete detailed mapping of the Dhar valley inlet and examine hypotheses relating to Dhar valley inlet formation. Previous authors have posited that the Dhar valley inlet formed as spring activity promoted drainage head erosion across the steep crater rim and/or that gullying concentrated in the north east of the crater due to water supply from higher elevation regions in that direction. We will also investigate whether a prominent fracture in the north east, and sub-vertical cooling fractures that trend NE-SW (an original basaltic flow feature), may have influenced the Dhar valley inlet formation.

Increased constraints on crater inlet valley incision mechanisms, controls, and rates, will help extrapolate our understanding of fluvial erosion to crater-dominated terrains, including key specific sites such as Jezero crater on Mars, and in generalized numerical simulations of cratered landscapes. This work will ultimately help place constraints on the extent, absolute timing, environments and mechanisms required to develop fluvial valleys around and into impact craters.

Field work is expected to be completed in early Spring 2023 and at EGU 2023 we will present preliminary findings from the field and detail our next steps moving forward. This work is possible thanks to funding from the Eugene and Carolyn Shoemaker Impact Crater Research Fund and graduate field work funding from the Jackson School of Geosciences. 

How to cite: Bamber, E., Goudge, T., Stucky de Quay, G., and Chandran, S.: Investigating Crater Inlet Valley Formation: Field Study at Lonar Crater, India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1437, https://doi.org/10.5194/egusphere-egu23-1437, 2023.

Martian gullies are alcove-channel-fan systems which have been hypothesized to be formed by the action of liquid water and brines, the effects of sublimating CO₂ ice or a combination of these processes. Recent activity and new flow deposits in these systems have shifted the leading hypothesis from water-based flows to CO₂-driven flows. This shift in thinking is supported by the low availability of atmospheric water under present Martian conditions and the observation that gully activity occurs at times when CO₂ ice is present. We recently performed novel experiments that have shown that this hypothesis holds; sediment can be mobilized and fluidized by sublimating CO₂ ice under Martian atmospheric pressure. However, if these flows are able to erode the underlying surface and can explain the formation of Martian gully systems over the long term remains unknown. Therefore, we present an additional series of experiments that test the capacity of CO₂-driven granular flows under Martian atmospheric conditions to erode sediment. These experiments were conducted in a 4 m long flume in the Aarhus Mars Simulation Wind Tunnel. Our experiments show that CO₂-driven granular flows can erode loose sediment under a range of different slopes and CO₂-ice fractions. The results also show that incorporation of warmer sediment increases fluidization of the mixture, reflected by an increase in gas pore pressure in the flow. These results thus prove that morphological evolution in the gully systems on Mars can be explained by CO₂-driven granular flows.

How to cite: Roelofs, L., Merrison, J., Conway, S., and de Haas, T.: CO2-driven granular flows as erosional forces on present-day Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2626, https://doi.org/10.5194/egusphere-egu23-2626, 2023.

Aeolian and fluvial processes on Earth show significant interactions. Within terrestrial desert environments, analysis of ~200 locations has revealed that where ephemeral or episodic rivers flow across a dune field the predominant processes alternate between aeolian and fluvial, and that when rivers and dunes are active, they interact with one another. Avulsions can be major, with channels in the northern Kalahari having cumulative diversions of 10s of km. Considering Mars likely had an arid environment during the period of peak fluvial activity, the presence of fossilised Martian dunes, and observations by the Curiosity rover of fluvially altered aeolian deposits, it is apparent that Mars likely experienced simultaneous fluvial and aeolian processes, and periods of fluvial inactivity where aeolian processes persisted. At present, Martian aeolian and fluvial processes have only been studied independently, and their interaction has not been explored.

Here we report the initial study by the Working group on Aeolian-Fluvial Terrain Interactions (WAFTI), based at the European Space Agency, which examines the effects of these processes in synergy under ancient Martian conditions, using a combination of modelling and geomorphological analysis. We hypothesise that these interactions could have implications for a number of Martian phenomena, for example: the prevalence of meandering inverted channel systems, the distribution of organic material, the discordance of Martian valley networks, and the sediment size and distribution of Martian rivers. In this study, we simulate the interactions between migrating dunes and different reaches of an active river channel, under ancient Martian conditions to determine the effects on the channel’s morphology and geometry.

Our Martian Aeolian-Fluvial Interactions (MAFI) model is a landscape evolution model based on a coupled implementation of the Caesar-Lisflood fluvial model, and Discrete ECogeomorphic Aeolian Landscape model (DECAL) dunes model. It routes water over a Digital Elevation Model (DEM) and calculates erosion and deposition from fluvial and slope processes changing elevations accordingly. Aeolian material is discretized into slabs on the DEM, and slabs are moved across the space according to a set of simple rules.

At EGU we will present the results of our simulations of aeolian and fluvial interactions on an inclined plane with a central channel and a continuously flowing Martian river. Typically on Mars, channels are housed within valleys with V or U-shaped cross-sections. Additionally, the topography of Mars is heavily altered by impact craters, many of which are sediment sinks. Finally, the profiles and immaturity of Martian valleys indicate that they were likely ephemeral/episodic, so flow was unlikely to be continuous. We, therefore, plan to expand our study to simulate the following: (1) simulate continuous flow for a DEM with a V-shaped valley and central channel; (2) “” U-shaped valley and central channel; (3) “” for a DEM with a crater present adjacent to the part of the valley; (4) simulate episodic fluid flow with periods of no fluvial activity, but continued aeolian activity. Understanding these two major surface processes in synergy will aid in the reconstruction of Mars’ ancient paleoenvironments in a way that has not previously been explored.

How to cite: Bahia, R., Bohacek, E., Braat, L., Boazman, S., Sefton-Nash, E., Orgel, C., Wilson, C., and Riu, L.: Modelling River-Dune Interactions on Ancient Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2810, https://doi.org/10.5194/egusphere-egu23-2810, 2023.

How to cite: Bohaceck, E. V., Bahia, R. S., Braat, L., Boazman, S., Sefton-Nash, E., Orgel, C., Wilson, C., and Riu, L.: Modelling River - Dunes Interactions on Titan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2831, https://doi.org/10.5194/egusphere-egu23-2831, 2023.

            River deltas and fluvial fans are both fan-shaped landforms that contain complex channel networks. Fan shaped landforms have also been identified on Mars at Jezero, Eberswalde, and Gale craters among many other locations. A principal distinction between these two landforms is that only deltas systematically form along the shorelines of a standing body of water. Fluvial fans may form along a body of water, but can also form hundreds of kilometers inland. It is thus crucial to be able to accurately distinguish between deltas and fluvial fans for the purposes of mapping paleo-shorelines on planetary bodies and understanding paleoclimates. In this work, we apply multiple quantitative methods on Martian fan-shaped landform channel networks to map channel networks to differentiate fluvial fans from river deltas on Mars. We quantify differences in channel bifurcation and divergence angles due to channel crossovers. We also measure changes in channel reach length between bifurcation and divergence nodes. Differences in channel networks occur because fluvial fans are built by channel bed aggradation and channel avulsion. River deltas are constructed by both mouth bar growth and consequent channel bifurcations, as well as infrequent avulsions. In river deltas on Earth, channel bifurcations form at an angle of approximately 72°. Channel lengths and widths in river deltas decrease downstream with increases in successive channel bifurcations. On the contrary, fluvial fan avulsions generate smaller divergence angles and down-fan channel narrowing is not necessarily linked to divergence nodes. This project applies Earth derived channel network mapping techniques to Martian fan-shaped landforms and demonstrates that this methodology is applicable on Mars. Preliminary analysis of the channel network of the Jezero crater landform suggests that it resembles a fluvial fan and not a delta. Conversely, preliminary analysis of the Eberswalde crater channel network suggests that the landform here does resemble an Earth river delta. Our results indicate that fan-shaped channel networks can and must be carefully assessed. This is especially true if the presence of deltas is used for the estimation of the location of paleo-shorelines on planetary bodies, as only deltas regularly form at shorelines. Alternatively, additional evidence is required to identify paleo-shorelines as fluvial fans may also form along shorelines. On Earth, fluvial fans are less sensitive to sea-level rise and coastal hazards than deltas and thus react differently from deltas due to changing sea levels.

How to cite: Gezovich, L., Plink-Bjorklund, P., and Henry, J.: Quantifying the Channel Networks of Fan-Shaped Landforms on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2928, https://doi.org/10.5194/egusphere-egu23-2928, 2023.

During the martian year the surface temperatures in winter dip below the condensation temperature of carbon dioxide and it freezes onto the surface. In the spring, it sublimates directly back into the atmosphere and observations reveal that this cycle of condensation-sublimation results in identifiable sediment transport on the martian surface. We use data from the Colour and Stereo Surface Imaging System (CaSSIS) on ESA's Exomars Trace Gas Orbiter to illustrate the range of landforms thought to be created by these sublimation processes. Previous experiments have revealed that condensation of CO₂ ice into the regolith pore space and its subsequent sublimation can result in downslope sediment transport. they also showed that aeolian sand was less prone to sediment motion triggered by sublimation than martian regolith simulant and it was suggested the presence of dust could be responsible for this difference. As dust is an important component of the martian atmosphere and surface, in these experiments we explore the influence of dust content on the sediment transport processes and capacity for sediment transport.

Our experimental setup consists of a liquid nitrogen cooled copper sample holder ~30cm long by 20 cm wide within which the sediment is formed into a slope at 30° (max. depth 10 cm). This container is placed inside the Open University’s Mars Chamber which has has a length of 2 m and a diameter of 1 m. One experiment typically takes 2hrs, and the preparation takes 12-14hrs. First the chamber is evacuated and backfilled with CO₂ gas twice to purge terrestrial gases including H₂O. Once this is complete the sample holder is cooled with liquid nitrogen until all the sediment temperatures reach the condensation temperature of CO₂. The experiment then starts and a heat lamp is used to force the CO₂ sublimation.  The experiments are monitored by an array of cameras for photogrammetry, a high definition video camera to record the processes, pressure gauges to maintain/monitor the pressure and thermocouples to monitor the sediment and surface temperature.

In this series of experiments we vary the dust content in an aeolian sand matrix from 0 to 20% by weight by adding the clay fraction of the MSC simulant. We find no significant difference in the results between 0 and 5% dust content, then at higher values the transported volume and activity increases suddenly and the transported volume and activity remains stable at a higher level from 10% dust upwards. Our results reveal that a sediment transport threshold seems to exist between 5% and 10% dust content and therefore this factor must be considered when studying seasonally active surface processes on Mars.

How to cite: Conway, S., Beck, C., Herny, C., Cesar, C., Sizemore, H., Sylvest, M., and Patel, M.: The effects of dust content on surface sediment transport by carbon dioxide ice sublimation on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3373, https://doi.org/10.5194/egusphere-egu23-3373, 2023.

Granulometry, shape, and chemical composition analyses of the sediments studied by the Opportunity rover along its entire 45-km-long traverse have been used to classify sediments and provide information about their origin and depositional processes.

We have conducted granulometry and shape analyses of 179 sediment targets visible in MI images [1]. To facilitate the analyses, we have used the PADM algorithm - a semi-automatic tool for particle detection, measurement, and analysis [2]. This allowed identification of more than 70000 individual grains. For chemical composition analysis we used APXS data of 62 sediment targets [3]. The normative mineral composition was calculated from APXS according to the CIPW procedure to calculate the estimated density of the material and to classify in QAPF system.

The analyses show five deposit classes: i) dust with very fine sand enriched in sulphur, ii) fine basaltic sand, iii) coarse sand enriched in iron, found only on the plains, iv) gravel enriched in iron, also found on the plains, and iv) gravel with a typical for basalts amount of iron, found at the Endeavour crater rim. These classes occur in the following geomorphological settings: i) dust mixed with very fine sand is common on the leeward side of topographical obstacles, ii) fine sand is present in depressions, iii) coarse sand is related to coarse-grained ripples fields, iv) gravel occur as a lag deposit, especially in coarse-grained ripple troughs and at crater rims and outcrops.

The typical diameter of grains for the fine sand is 0.13 mm, and for the coarse sand - 1.20 mm. The best sorted coarse sands were found on the slopes and the crests of coarse-grained ripples. In most cases, the normative mineral composition of deposits fits in the basalt/andesite field of the QAPF classification. The coarse sand found in coarse-grained ripples was characterized by the highest content of iron and shows the most mafic composition in the QAPF diagram. This deviation from the basalt composition is related to iron-rich spherules (a frequent component of the gravel) than to a more mafic type of rock. On the other hand, the coarse sand grains found in ripple fields were characterized by lower roundness than the iron-rich spherules. Therefore, many of the transported by wind coarse sand grains had their origin in partial fragmentation of iron-rich spherules.

The work was funded by the Anthropocene Priority Research Area budget under the program "Excellence Initiative – Research University" at the Jagiellonian University.

[1] Herkenhoff, K. E. (2003) MER1 Microscopic Imager Science Calibrated Data Bundle. PDS Geosciences Node. DOI: 10.17189/1519006

[2] Kozakiewicz, J. (2018). Image Analysis Algorithm for Detection and Measurement of Martian Sand Grains. Earth Science Informatics, 11, 257-272. DOI: 10.1007/s12145-018-0333-y

[3] Gellert, R. (2009). MER APXS Derived Oxide Data Bundle. PDS Geosciences (GEO) Node. DOI: 10.17189/1518973

How to cite: Kozakiewicz, J., Kania, M., Salata, D., and Nowak, L.: Sand properties investigation at Meridiani Planum, Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3863, https://doi.org/10.5194/egusphere-egu23-3863, 2023.

NASA's Solar System Treks Project (SSTP) online portals provide web-based suites of interactive visualization and analysis tools to enable planetary scientists, mission planners, students, and the general public to access mapped data products from past and current missions for a growing number of planetary bodies. 

The Solar System Treks portals provide advanced data visualization and analysis capabilities for data returned from a vast number of instruments aboard many past and current missions to a growing number of planetary bodies throughout Solar System. Multiple map projections as well as interactive 3D views are available to optimize visualization of different landforms. A detailed set of analysis tools helps users find and interpret morphological features across diverse landscapes on the surfaces of planets, moons, and asteroids. In some cases, these tools make use of machine learning and artificial intelligence to help users locate, identify, and understand landforms drawn from very large datasets. Having an integrated suite of portals presenting geomorphology across a range of planetary bodies within the Solar System greatly facilitates studies of comparative planetology. The portals are currently being used for site selection and analysis by NASA and its international and commercial partners supporting upcoming missions. 
Today, 11 web portals in the program are available to the public. This list includes portals for the Moon; the planets Mercury, Venus, and Mars; the asteroids Bennu, Ryugu, Vesta, and Ceres; and the outer moons Titan and Europa. The Icy Moons Trek portal features seven of Saturn’s smaller icy moons. All of the portals are unified under a project home site with supporting content. These web-based portals are free resources and publicly available. 

This presentation for EGU will detail and share examples of the how the portals can be applied to research in planetary geomorphology.

How to cite: Day, B. and Law, E.: Exploring Planetary Geomorphology with NASA’s Solar System Treks, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3981, https://doi.org/10.5194/egusphere-egu23-3981, 2023.

Geomorphological analogues provide a valuable perspective for understanding planetary volcanic structures, landforms, and processes. Arabia Terra, Mars contains numerous collapse structures that are somewhat controversially interpreted as calderas. This work aims to use planetary analogues to shed further light on possible martian caldera collapse and volcanic processes.

The project had a focus on a population of underrecognized ancient volcanic constructs that associated with explosive and effusive volcanism, termed “plains-style caldera complexes” (Michalski and Bleacher, 2013), that are present within the Arabia Terra and perhaps across the Noachian-Hesperian crust on Mars. These features are characterised by deep crustal collapse, presence of flow deposits, potential pyroclastic materials, and more importantly, without a pronounced central edifice. Notable examples of the plains-style caldera complexes includes: Eden Patera (33.5°N, 348.8°E), type-locality of the plains-style caldera complexes; Siloe Patera (35.3°N, 6.55°E), which presents two overlapping classic piston-type caldera collapse; and Hiddekel Cavus (29.4°N, 16.2°E), a narrow, cone-shaped depression with extremely high depth/diameter ratio. In this project, besides working on Martian satellite imagery and topographic data, terrestrial analogue study was also a useful tool when analysing caldera floor geomorphology at Eden Patera. 

The Hawaiian volcanoes have previously been used as analogues for certain volcanic processes on Mars (Mouginis-Mark et al., 2007; Hauber et al., 2009). Though the Hawaiian volcanoes formed through different volcanic styles than the plains style caldera complexes, they nonetheless provide insight into key processes. At Kīlauea volcano, Hawaiʻi, the caldera collapse and volcanic deposits were associated with Hawaiian-style effusive eruption of basaltic lava, accompanied by minor explosive eruptions (Stovall et al., 2011; Patrick et al., 2020). Kīlauea Iki and Halemaʻumaʻu, the pit craters of Kīlauea, were considered as potential terrestrial analogue for (1) the “black ledge” formation (chilled lava lake margin feature) and (2) isolated “islands” of pyroclastic materials on the caldera floor at the Eden Patera, and both features are important evidence supporting a volcanic story, as well as both effusive and explosive activities of the Eden Patera caldera complex.

Nonetheless, potential analogue for caldera collapse mechanism was once again identified at Kīlauea Halemaʻumaʻufor an unnamed cavus of possible volcanic origin within the mid-Noachian to Hesperian plain of Xanthe Terra, Mars (Tanaka et al., 2014). Both the Hawaiian pit crater and Martian cavus are deep depressions with steep scarps, overlying a region of extensive concentric faults and fractured crust, making Kīlauea a good candidate for future analysis as a terrestrial analogue for caldera features of the plains-style caldera complexes on Mars.

How to cite: Chu, Y. Y. and Michalski, J. R.: Geomorphic study of caldera features on Mars with the help of Earth analogues, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4080, https://doi.org/10.5194/egusphere-egu23-4080, 2023.

The Gusev crater, landing site of the MER-A mission, and the Jezero crater, site of the Mars2020 mission, currently located near the Martian equator. They may have been two fluvial-lacustrine systems from the planet's wet past, Nevertheless, cortical fractures, ridges and basaltic flows are present in the bottom of both craters. These features are well preserved and not affected by large craters, which seems to indicate that could be young and contemporary forms. Mapping of both Gusev Crater and Jezero Crater has been carried out by remote sensing onboard the Mars Reconnaissance Orbiter (MRO), of particular interest for Gusev Crater is the Context Camera (CTX)-based high-detail mapping, which improves the resolution of previous studies, and the High-Resolution Imaging Experiment (HiRISE). These are complemented by data from the Thermal Emission Imaging System (THEMIS) and Mars Orbiter Laser Altimeter (MOLA), the Mars Global Surveyor (MGS) mission. CTX and HiRISE are visible images that provide information about the surface features of morphological units in detail. The MOLA data have made it possible to determine the stratigraphic position of the mapped units and to obtain information on the slopes and elevations of the units, as well as to estimate the fill of both craters. The combination and analysis of these data show possible evidence of geological activity on the surface of these craters in more recent periods of Mars' past (millions of years). Crater counts (crater frequency) have been used to determine a possible age for the ridges described in crater Gusev. These indications may be associated with volcanic activity and horizontal “strike-slip” movements affecting the ridges observed in Gusev crater, as well as crustal fracture and the presence of basaltic plains in Jezero crater.

How to cite: Anangonó Tutasig, R. S., Fernández Menéndez, S. C., Fernández Calleja, J., Díez Alonso, E., and De Cos Juez, J.: Evidence of late Mars geological activity on the floor of the Gusev and Jezero craters. Landing sites of NASA's Mars exploration missions., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4549, https://doi.org/10.5194/egusphere-egu23-4549, 2023.

This research deals with the detailed study of some global-scale geomorphological structures on Mars to identify possible current or fossil methane emission points. For years, attempts have been made to understand the mechanism that led to the formation of methane on Mars and how it may have been stored to date in subsurface reservoirs. From the data recently received from satellites (Tracer Gas Orbiter on board of ExoMars, Planetary Fourier Spectrometer on Mars Express) and rovers (Mars Science Laboratory Curiosity in Gale crater) on Mars, it is possible to infer that the methane on Mars is gradually emitted into the atmosphere and most of the times is detected by these instruments. Thanks to these dataset of methane emissions during the years (since 2004 with the PFS first detections) it is possible to trace the possible points in which the upper limit concentration of methane are equal to or greater than 10 p.b.b.v. so as to select a few areas where to begin the geomorphological and mineralogical analyses for this research in order to create a global map of possible areas where current methane emissions from subsurface methane reservoirs may be recorded. For this study the focus will be on hectometric to kilometric mounds of volcanic or sedimentary origin (mud volcanoes and/or pingos like structures), chaotic terrains and fracture fields in sedimentary piles. The areas selected for this research are Coprates and Candor Chasma (Valles Marineris, Mars), Nili Fossae (Mars), Vernal crater and the surrounding of Arabia Terra (Mars) and Gale crater (Mars). All of these locations have key characteristics such as proximity to a boundary zone (Gale crater), the presence of a fracture system (Nili Fossae), presence of mud volcanoes or pingoes (Valles Marineris and Utopia Planitia): all possible incentives for the presence of methane emission spots. The aim of this project, as already mentioned, will therefore be to analyse these areas in detail, trying to understand whether they could be or have been methane emission points, with the help of the planetary analogues that can be found in Azerbaijan regarding mud volcanoes, in Canada for pingos or fracture systems in China.

How to cite: Mariani, E. and Allemand, P.: Methane on Mars: Correlation of geomorphological features with current methane emissions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5338, https://doi.org/10.5194/egusphere-egu23-5338, 2023.

Shalbatana Vallis is a valley located in the Oxia Palus quadrangle, characterized by a simple system and a homogeneous coverage. Shalbatana vallis flows into the Chryse Planitia basin, alongside Ares Vallis, Kasei Valles, Simud Valles and Tiu Valles. The valley is affected in different points by landslides with various surfaces and elongations. Landslides on Mars are a topic already studied by other authors. However, the problem of the dynamic of such structures remains debated. The landslides of Shalbatana Vallis occurred in a homogeneous lithology and in a valley with a quite constant depth. We first present the ages of the landslide and discuss the age distribution. The, we present a geometrical analysis of the landslides (surface, elongation, volume, runout, etc….) and use these parameters to constrain some dynamical properties (possible velocity, possible loss of volatiles) and to discuss possible triggering mechanisms.

How to cite: Soldano, M. and Allemand, P.: Characterization of Shalbatana Vallis landslides, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7284, https://doi.org/10.5194/egusphere-egu23-7284, 2023.

How to cite: Patočka, V., Kihoulou, M., and Čadek, O.: Dynamic reorientation of tidally locked bodies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7673, https://doi.org/10.5194/egusphere-egu23-7673, 2023.

On Earth, the characteristics of fluvial erosion depends on two main parameters: climate (rain fall) and tectonic history. Mars is a planet that experienced erosion driven by liquid water but its geodynamics are vastly different from Earth’s. Mars therefore represents a unique opportunity to understand how landscape evolution differs on a planet with a “stagnant lid” tectonic regime. The formation of Tharsis dome, a vast volcanic province, during the early history of Mars represented a major magmato-tectonic upheaval for the planet. Over several hundreds of million years, the Tharsis region experienced large scale magmatic intrusions, crustal deformation and effusive volcanism resulting in crustal growth, dynamic uplift and true polar wander (TPW) that accounts for the present location of the Tharsis dome at the equator. This event occurred during a time when Mars had an active water cycle, although the total mass and relative proportion of ice, liquid water and vapor is not well constrained. The uplift and subsequent true polar wander of Mars have affected drainage systems across the planet with many being abandoned or modified due to the variable uplift or subsidence as a lithospheric response to the regional upheaval in the Tharsis region (load on the elastic lithosphere) and TPW. Here we present results from numerical simulations performed using a stream power law algorithm on Mars during the Noachian/Hesperian growth of Tharsis to assess how the patterns of erosion rate are affected by the distribution of atmospheric moisture and flow routing in an attempt to reproduce the observed distribution of valley networks and their geometry. For this, we adapted and used the fully-implicit and O(n)-complexity FastScape algorithm to perform the simulation at the planetary scale. The aims of this work are to quantify the effect of Tharsis dome formation on fluvial systems during the Noachian and early Hesperian, and to establish a first-order erosion rate for this period. This study could help to constrain how much water was cycling on Mars at this time.

How to cite: Davies, H. S., Bouley, S., Baratoux, D., and Braun, J.: What role did Tharsis formation during the Noachian/Hesperian period (3.8 – 3.5 Ga) have on the erosional history of Mars?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8505, https://doi.org/10.5194/egusphere-egu23-8505, 2023.

Defining criteria for mapping material units on airless, rocky bodies is challenging. Where the primary geologic process for most of a body’s history is impact cratering, traditional morphology-based mapping approaches may fail, because differences in morphologic characteristics among the various cratered surfaces can be hard to discern, and surface morphology is muted by the regolith’s physical and mechanical properties. In constructing a global geologic map of Vesta at 1:300,000-scale using the Dawn Framing Camera (FC), DTM-derived slope and contour, and multispectral data, we have countered this problem by utilizing a hybrid method of mapping that first requires creating two maps independently. The first map depends on morphology and topography to define map units, while the second uses spectral data to define units. The unique results of each map are then combined into the hybrid map units. 

Multispectral data provide unique insight into stratigraphy (material brought up through cratering processes) that is easily lost when using an albedo mosaic as the basemap. However, solely using a “color” ratio mosaic as a basemap easily magnifies potentially misleading data, because spectroscopy in the shorter wavelengths (UV-VIS-near IR) can only sample the upper few µm of the surface, and very little unique material is required to affect the signal of a regolith. Contacts defined by multispectral data may not coincide with clear morphologic boundaries as a result, so caution must be used in how the two maps are merged and clear criteria should be established to define hybrid map units.

We found that the crucial exercise in ensuring unique data were retained when combining these two maps was to create a decision tree for determining which data would be primary in choosing where to draw unit boundaries. We divided the decision tree into the following if-then statements:

• If saturated colors (meaning the color signal in color-ratio spectral data was strong and the color itself was easy to describe) matched unit boundaries derived from morphology, there was no conflict. For example, saturated colors on Vesta tend to be associated with fresher expressions or exposures of regolith, which are more likely found at the youngest, freshest craters/ejecta, easily demarcated morphologically.
• If muted colors exist, where the morphology is relatively clear, the morphology is the primary guide for unit definition, as it retains the least altered record of geologic processes and the most reliable record of the nature of the rock bodies. Colors provide additional characteristics of such units, allowing for some interpretation of composition.
• If saturated colors are not associated with morphologic boundaries, the color boundaries are interpreted to record the most recent (even if very thin) impact evidence. In such cases we have mapped the saturated color data as impact material. This preserves the underlying morphology/topography information while supporting stratigraphic interpretations based on excavated subsurface layers revealed by crater ejecta.
• In the case of muted colors where the morphology is unclear, decisions must be made case-by-case, using all available data to make a reasonable determination of where to mark unit boundaries.

How to cite: Yingst, R. A., Mest, S. C., Garry, W. B., Williams, D., Berman, D., and Gregg, T. K. P.: Mapping Vesta using a hybrid method for incorporating spectroscopic and morphologic data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8552, https://doi.org/10.5194/egusphere-egu23-8552, 2023.

Aeolian sand transport on Mars is active today and was likely so throughout its history. Widespread dune motion is theorized to comminute sand to sub-sand sizes, a process also implied by lab experiments. In view of this sand destruction, discovering the source(s) and origin(s) of Martian sand provides critical information for understanding Martian sediment cycling.

Local sand sources have been discovered and considered to be consistent with the long-standing hypothesis for Martian sand as volcaniclastic in origin. A local source of Martian sand has recently been inferred in the western Medusae Fossae Formation (wMFF). Given the pyroclastic origin of the vast MFF, the new discovery of sand generation from that deposit substantiates a volcaniclastic origin of Martian sand.

However, the wMFF is limited in extent and unlikely to constitute an origin for the globally distributed dune fields on Mars. Continued exploration for sand origins is needed to explain this widespread distribution.

We examined the five global geological units interpreted as volcaniclastic, which yielded limited evidence of sand sourcing outside the wMFF. In these five units, sand sourcing was detected in visible-wavelength data in the Hesperian and Amazonian transitional units that comprise the central and eastern MFF and in the Noachian units of Arabia Terra. Investigation to characterize sand production from these units is revealing a variety of sand source outcrops.

Tracing sand deposits back to their sources is another approach for determining sand origins, as was used in determining the source – and thereby the origin – of sand in and from the wMFF. Determining sources for the widespread sand on Mars requires determining sand survivability: how far could sand travel from their sources before being destroyed by comminution to sub sand sizes? Simulation of aeolian transport on Mars has shown different sand mineralogies comminuting at different rates, suggesting that the bulk mineralogy of a sediment may change with increased transport distance. Building on that previous experimental work, we are undertaking comminution of 14 different Mars-analog sands to more fully characterize the mineralogical and physical effects on sand of aeolian transport. The results will support using dune sand compositions and distances from possible source outcrops to test if these outcrops sourced the sand.

Thermal inertia is used to characterize Martian sand, e.g., to estimate grain sizes. Available dune field mapping facilitates investigation into dune sand thermal inertia values, thereby providing data, e.g., on sand particle sizes and induration states. As available mapping incorporates non-sand substrate, we are remapping dune fields to include only visible sand and using the distributions of thermal inertia values to assess if non-sand substrate is still included in our mapping. Having completed remapping of tropical dune fields, we are beginning analysis of their thermal inertia values. The results will reveal any trends relative to geography, underlying geologic unit, elevation, and other factors.

These three investigations – into the sources and origins, effects of transport, and thermal inertia values of Martian sand – will support improved understanding of Martian aeolian sand cycling, one of the most active geologic agents on Mars.

How to cite: Burr, D., Finch, J., Baker, A., Fry, R., Nguyen, V. N., and Chinchkhede, T.: How does sediment cycling work on Mars? Three investigations into the cycling of Martian aeolian sand, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8692, https://doi.org/10.5194/egusphere-egu23-8692, 2023.

Introduction: The WGCCRE has made recommendations regarding the lunar reference frame (LRF) [1]. Over the last 2 years both the Artemis III SDT report [2] and the LEAG-MAPSIT LCDP SAT report [3] have included recommendations for an updated lunar reference frame. Park et al. [4] have published new Solar System ephemeris results that include a new lunar laser ranging (LLR) solution and lunar orientation ephemerides. The latter includes the DE440 ephemeris in the Mean Earth/polar axis (ME) frame, which is compatible with their earlier DE421 ME frame recommended for use by the WGCCRE.

Given the recent activities and interest on the LRF, and the expected increase in lunar missions by the various nations, it is appropriate for the WGCCRE to consider updating the recommendations on a LRF. We are soliciting input on such a recommendation.

Issues to consider: The Moon is one of few bodies in the Solar System without a specific longitude defining feature. It may be timely to use an LLR solution to define the LRF, following long-standing IAU and WGCCRE recommendations [1, p. 7]. Currently, a particular such LLR solution is already the underlying basis for the DE421 ME frame. Such a solution and similar future improved solutions could instead serve to directly define the frame in the ME system, and in practice would match in a no-net rotation sense the existing recommended DE421 ME frame.

Separately, the lunar orientation model could now be specified by using the JPL DE440 ephemeris in the ME frame. The new JPL solutions use substantially more available data, and improved modeling compared to the previous (2008) DE421 solution. Differences from the previous model are less than 1 meter during the period 1900–2050. Differences in the underlying LLR solutions are < 1.5 meters. Such differences are not so significant as to be noticeable in the positioning of data products except at the highest current levels of accuracy. This update would nevertheless help to prepare for the best future accuracy by removing one source of error.

We will present the benefits of updating the LRF and weigh them against the burden of changing the established definition.

Request for input: The WGCCRE is requesting feedback from the lunar community on these issues. Is using (the current new JPL) LLR solution to define the LRF appropriate? Is using the DE440 ephemeris in the DE421 ME frame appropriate as a new lunar orientation model? Are there other LLR and lunar ephemeris solutions that could be considered for use in this process? Feedback to the lead author is welcome, preferably by the time of or at the EGU meeting. We hope to complete the next version of our main WGCCRE report this year and possibly include an update for a recommended LRF definition.

References: [1] Archinal et al. (2018) CMDA 130:22. [2] NASA (2020) NASA/SP-20205009602. [3] LEAG-MAPSIT Special Action Team (2021), see MAPSIT website. [4] Park et al. (2021) The JPL Planetary and Lunar Ephemerides DE440 and DE441, Astron. J. 161(3), 105.

How to cite: Archinal, B. and Working Group on Cartographic Coordinates and Rotational Elements, I. A. U.: Updating the Lunar Reference Frame, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9136, 2023.

There are several active geologic processes on Mars today one of which is the formation of slope streaks. Slope streaks are a widespread and relatively common process that were first observed as dark fan-shaped features with lobed ends in Viking Orbiter images taken in 1977 (Morris, 1982; Ferguson and Lucchitta, 1984). Investigation of repeat images identified slope streaks as relatively low-albedo features that vary in width (up to 200 m wide) and length (up to a few kilometers long) (Sullivan et al., 2001). Although it was assumed that the slope streaks formed on steep slopes >20°, the slopes were not resolved due to the resolution limit of the data. Slope streaks have been found to form in high-albedo dusty regions on Mars, concentrated around the equator between 39°N and 28°S (Sullivan et al., 2001; Schorghofer and King, 2011; Heyer et al., 2019). Additionally, slope streaks have been observed to fade over decades and high-albedo slope streaks have also been observed (interpreted to be faded slope streaks) (Schorghofer et al., 2007). The formation of slope streaks has previously been observed to be inconsistent spatially and temporally (Schorghofer and King, 2011); however, more recent research has identified seasonal variations of formation, with the highest rates of formation occurring in the fall (near Ls 190) (Heyer et al., 2019). There are many proposed formation mechanisms for slope streaks that fall into either a dry or wet mechanism category. The dry mechanism involves a granular flow triggered by a disturbance mechanism (e.g. dust devil or meteorite impact), while a wet mechanism would indicate a debris flow triggered by a phase change of H₂O (e.g. melting of ice to trigger groundwater discharge). Research presented here investigates the slope profiles of identified slope streaks to further understand and constrain the formation mechanism. We investigated 13 well-monitored slope streak sites. Using Arcmap we identified slope streaks within each site with a polyline. For each site we identified CTX stereopairs, processed each image using the Integrated Software for Imagers and Spectrometers (ISIS3), and then used Ames Stereo Pipeline (ASP) to create digital elevation models (DEM) for each site. In Arcmap using the DEMs and the polylines for each slope streak we extracted the slope profiles to determine the starting and stopping slope of each slope streak and then average slope of the entire slope streak. Results indicate that on average slope streaks starts at a slope of 24° and end on a slope of 16° with the ending slope decreasing with increasing flow distance. Also, the majority of slope streaks start on a slope <30°, which is near the dynamic angle of repose. The low start angle and the decreasing stop angle with flow distances indicates an energetic triggering mechanism may be necessary to create a slope streak. Recent research from Heyer et al. (2020) identified dust devil tracks that appear to have triggered slope streaks, supporting our results that are most consistent with a dry and energetic triggering mechanism.

How to cite: Hoover, R., Stillman, D., Primm, K., Kaplan, H., Michaels, T., and Fenton, L.: Slope Profile of Slope Streaks Indicate an Energetic Triggering Mechanism, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10690, https://doi.org/10.5194/egusphere-egu23-10690, 2023.

ExoMars is an astrobiology program led by the European Space Agency, which aims to launch a rover to Oxia Planum to search for signs of past life. Although the primary goal of the mission is focused on astrobiology, there are several secondary mission objectives, such as investigating the geomorphology, aeolian and volcanic processes to better understand the evolution and paleoclimate of Mars. CLUPI (a close-up imager) will be used to acquire high-resolution images of rocks, geological outcrops, and drill cores to provide the overview on the geology of Oxia Planum. Due to the limited amount of data that can be transmitted at once from Mars, only few CLUPI images will be available daily to the science team for assessing hypotheses and decide how to program the rover of the next cycle of activities. Thus, it is curial that each CLUPI image will contain a maximum of relevant information. For this reason, we are conducting preparatory tests and simulations to identify ideal CLUPI working conditions in view of the prime mission on Mars. In this work, we specifically explored the impact that different illumination conditions (i.e., direction of the illumination axis and intensity of direct light vs diffused light) may have on the detection of textures and sedimentary structures in close-up images. We showed that by acquiring images at different type of day, under specific lighting conditions, it is possible to enhance the probability of detecting various rock textures and geological samples, which can contribute to the diverse data collection and answer main question about the geomorphology of Oxia Planum.

How to cite: Kuhn, N. J., Ligeza, G., Bontognali, T., Josset, J.-L., and Kuhn, B.: Exploring biosignatures and geomorphology of Mars with close-up images – preparatory activities for the ExoMars mission., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10961, https://doi.org/10.5194/egusphere-egu23-10961, 2023.

The second-largest valley on Mars is Kasei Valles. This research focuses on the landforms produced by surface processes in the southern branch of Kasei Valles’s midstream. By using cross-cutting relationships, and empirical crater dating of landforms, we constructed a morpho-stratigraphical chronology of the valles. Landforms such as deeply eroded canyons, colluvial fans, landslides, topographic barriers, terraces, and trim lines are typical landforms that have been formed by surface processes.

Our geomorphic mapping reveals that the valles were temporarily obstructed by two colluvial fans and a landslide, creating topographical obstacles to impound fluids (e.g lava, mudflow, water). The toe of the alluvial fans and the landslide were eroded by flights of terraces and trim lines, indicating a temporary, water-like liquid presence in the channel of the valles. The surface texture of the terrace surfaces indicates that the terrace staircases were probably created by a water-like fluid that stagnated and fluctuated for a while before the final evacuation.

The chronology of these important events indicates that colluvial fans were deposited in two temporal clusters. The first colluvial fan generation was formed in the Early Amazonian period (1.74-1.14 Ga), and the second colluvial fan generation was formed in the Late-Middle Amazonian period (307 Ma). The landslide is significantly younger and is estimated to have formed 122 Ma ago. The floor of the valles’s channel is covered by platy-textured material, which was formed 90 Ma ago as lavas or mudflows, which is the youngest studied geomorphologic feature. The age of the landslide and valles’s floor help us to constrain the timing of erosional processes responsible for the flights of terraces and trimlines, which stretch along approximately 60 km from up to downstream. Accordingly, these features should be formed between 122 Ma and 90 Ma. We believe that the genesis of these features (terraces and trimlines) is associated with a Newtonian fluid (such as water) that ponded behind the colluvial fan dams and the climatic conditions that allow this fluid to stagnate over brief periods of time enough to form terraces and trimlines. 

How to cite: Yazıcı, D., Yıldırım, C., and Görüm, T.: Landforms and chronologies in the southern branch of Kasei Valles, MARS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11911, https://doi.org/10.5194/egusphere-egu23-11911, 2023.

Tolstoj quadrangle is located in the equatorial area of Mercury, between 22.5°N and 22.5°S of latitude and 144° and 216°E of latitude. In this work we present the preliminary results of a geological map (1:3M scale). The main basemap used for the mapping is the MDIS (Mercury Dual Imaging System) 166 m/pixel BDR (map-projected Basemap reduced Data Record) monochrome mosaic compiled using NAC (Narrow Angle Camera) and WAC (Wide Angle Camera) 750 nm-images. Moreover, to distinguish spectral characteristics and topography of the surface, MDIS global color mosaics (Denevi et al., 2016) and the MDIS global DEM (Becker et al., 2009), have been taken into account. Then, the quadrangle has been mapped using ArcGIS at an average scale of 1:400k for a final out-put of 1:3M. So far, most of the geological contacts and lineaments of Tolstoj quadrangle have been mapped. The preliminary geological map shows the Caloris basin-related features dominating the Tolstoj quadrangle. The southern half of the basin is located in the upper left corner of quadrangle and interior and exterior smooth plains of the Caloris basin are the most extended volcanic deposits emplaced in the area. Also structural framework is mainly linked with the basin with radial and concentric grabens located in its floor and wrinkle ridges widespread both on the interior and exterior Caloris smooth plains. Further, thrusts have been detected on the quadrangle. They are located outside the Caloris basin but they are absent within its floor. Besides smooth plains, products of effusive volcanism, features related to explosive volcanism are also frequently detected. Interestingly, several volcanic vents have been identified in the inner Caloris smooth plains, aligned with the rim of Caloris basin. They were surrounded by extended pyroclastic deposits appearing in bright yellow in MDIS enhanced global color mosaics. However, vents are not clustered only inside Caloris basin, but other crater floors are affected by this type of features. Finally, few hollow fields have been detected, mainly located within crater floors.

Once the mapping activity is accomplished, the geological map will be integrated into the global 1:3M geological map of Mercury (Galluzzi et al., 2021), which is being prepared in support to ESA/JAXA (European Space Agency, Japan Aerospace Agency) BepiColombo mission.

Acknowledgements:  We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0

References:

Becker K. J., et al. AGU, Fall Meeting, ab-stract#P21A-1189, 2009

Denevi et al.:LPS XLVII. Abstract#1264, 2016

Galluzzi V. et al.:. Planetary Geologic Mappers 2021, LPI #2610, 2021

How to cite: Giacomini, L., Guzzetta, L., Galluzzi, V., Ferranti, L., and Palumbo, P.: Preliminary results of Tolstoj quadrangle (H08) geological mapping, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12945, https://doi.org/10.5194/egusphere-egu23-12945, 2023.

 Landscape Evolution Models (LEM) play a vital role in illustrating the complex landscape
responses to various geomorphic processes. These models favour replicating various evolution
processes over an extensive range of temporal and spatial scales. LEMs are also suitable for
simulating the effect of volcanic activity on landscape features. Olympus Mons, the largest
shield volcano in our solar system, acts as the perfect landform for this analysis. Tharsis
Volcanic Landforms on Mars, such as Olympus Mons and Tharsis Montes, are considered
analogues of basaltic shield volcanoes on Earth. The shield volcanoes of Tharsis are compared
to terrestrial Hawaiian volcanoes and Deccan volcanism and are often interpreted as hotspot
plume volcanism. The stream power incision model (SPIM) is used in landscape evolution
models to simulate river incisions. In this study, we utilised LandLab software to perform
numerical evolution modelling on Olympus Mons. The initial topography of the research
region is established using a DEM, and the maximum elevation of Olympus Mons is 21241.0
metres. The erodibility (Ksp) value, based on the lithological and climatic conditions, is taken
as 1 𝑀𝑎– ¹ under Hawaiian conditions considering the basaltic type rock property of Olympus
mons. With a concavity index value of 0.5 and zero upliftment, the model is run for 100000
years to observe its evolution. Our results reveal a change in the maximum elevation of 21241.0
to 21179.68, i.e., 124 m, due to the process of erosion. The results give an idea about how the
original volcanic landform, like that of Hawaii, must have shaped into the present landform
due to various geomorphic factors. 

How to cite: Sonowal, S., Narayan M, U., Ahmad, A., and Nair, A. M.: Landform Evolution Modelling of Volcanic Landforms using Landlab: A case study of Olympus Mons, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13051, https://doi.org/10.5194/egusphere-egu23-13051, 2023.

The Context Camera (CTX) on board NASA's Mars Reconnaissance Orbiter (MRO) has been in orbit since 2006 and has so far delivered more than 130,000 images. The images are one of the most popular data sets for planetary geologists because the data cover almost the entire planet and have good radiometric resolution, allowing very detailed interpretation of surface features. Since the beginning of the mission, the images have exhibited a darkening effect from the centre of the images towards the edges, creating visible seam lines when multiple images are stitched together. Due to the symmetric decrease in reflectance plots averaged over all lines, this problem is often referred to as "frowning" (see Figure 1 left). Since the standard calibration routines of the Integrated Software for Imagers and Spectrometers (ISIS) only include flatfield files for the first year of the mission, there are no quick and easy standard methods to correct for these artefacts. In this work, we provide an extended in-flight radiometric calibration and the resulting flatfield files that can be used directly in the ISIS environment (see correction example in Figure 1 right). The files are updated regularly and are permanently available in this repository: https://dx.doi.org/10.17169/refubium-37236 .

Figure 1: left: CTX image N05_064260_1638 with standard ISIS calibration applied (top) and curve plot of all averaged lines (bottom); right: after additional in-flight calibration the image (top) shows less darkening to the borders and the downward trent in the plot has been removed.

In addition, we are in the process of updating our "integrated Mars analysis and research system" (iMars) to include the full set of CTX images, which will be readily processed and made available for download in GIS-compatible formats. As with the previous system, users can select the footprints and visualise the data directly in the map view. Special tools for switching between images with multiple coverage provide an excellent infrastructure for analysing surface changes and seasonal or interannual variations.  We have made a complete overhaul of the graphical interface, which is accessible under https://maps.planet.fu-berlin.de/ctx . 

This work is supported by the German Space Agency (DLR Bonn), grant 50 OO 2204, on behalf of the German Federal Ministry for Economic Affairs and Energy. We thank the HPC Service of Freie Universität Berlin for computing time.

How to cite: Walter, S. H. G., Munteanu, R. R. C., and Aye, M.: CTX in-flight calibration and data dissemination, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13656, https://doi.org/10.5194/egusphere-egu23-13656, 2023.

The current approach for ortho-rectifying images taken by the Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO) uses MOLA data as a global reference ([1]), but this approach is imprecise, specifically at the equator, due to the large difference in spatial resolution between the two datasets (6 vs 463 m/pix).  Automatic point matching of image pixels to DTM pixels are not reliable, therefore usually the CTX pixels are matched to imagery datasets which are themselves controlled to MOLA, such as the THEMIS IR dataset ([2]).

The HRSC team is working on creating global mosaics of bundle-block-adjusted digital terrain models (DTMs) and corresponding image mosaics with better internal photogrammetric precision than the 50 m used as the grid size, and less deviation from MOLA profile heights, aimed to be finished by the end of 2023. 

This abstract presents our progress in using a new approach, by using HRSC DTMs as the global reference for CTX image rectification instead of MOLA, which involves using the HRSC ortho-image for co-registration of CTX images and applying brightness correction before combining all images of a quadrangle together to form a seamless mosaic which is then exported as a single image file. 

The workflow and processing is performed using modern pixel registration techniques, the USGS’ ISIS system, a database management system, and high-performance computing, and results in significantly less pixel offsets compared to the previous approach.

References[1] J. L. Dickson et al., LPSC 49, #2480. [2] S. J. Robbins et al., LPSC 52, #2066. 

Acknowledgements: This work is supported by the German Space Agency (DLR Bonn), grant 50OO2204, on behalf of the German Federal Ministry for Economic Affairs and Climate Action. We thank the HPC Service of FU for computing time.

How to cite: Aye, M., Walter, S. H. G., and Postberg, F.: Coregistration of CTX images to HRSC Global Datasets, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14806, https://doi.org/10.5194/egusphere-egu23-14806, 2023.

Eskers are sinuous sedimentary ridges formed in meltwater-filled subglacial tunnels. They are widespread in formerly glaciated landscapes on Earth. A small but growing number of late Amazonian-aged (~110-330 Ma) candidate eskers have been identified in Mars’ mid-latitudes in association with extant buried glaciers. These eskers are thought to have formed during periods when mid-latitude glaciation on Mars was more extensive than at present, due to variations in planetary spin-axis obliquity. The basal melting required for esker formation seems likely to have required elevated local or regional geothermal heating.

A recent study using current terrestrial theories for subglacial water flow adapted for Mars suggests that, if water was present beneath Martian ice masses, lower gravity favours the formation of efficient, tunnel-based drainage, as opposed to water flow through a distributed system of small cavities linked by water-filled orifices which is favoured for terrestrial ice masses. Tunnel-based drainage systems are more efficient, leading to lower water pressures and gradients, and slower water velocity.  Our previous experiments with a Mars-adapted model of esker sedimentation also suggest that, once a subglacial tunnel has formed, sediment deposition occurs more readily on Mars than Earth, as the lower gravity, and consequent lower water pressure and velocity, allows more rapid deposition.

These factors suggest that if subglacial water and mobilised sediment are present beneath Martian ice masses, esker formation is more likely on Mars than Earth as subglacial tunnels would be more widespread, and sediment deposition within them more rapid. However, this leads to questions regarding the likely source(s) of esker-forming sediment, and the water volumes needed to erode it. Initial calculations with a Mars-adapted model for erosion by subglacial water suggest that for a particle size typical of Martian sandy regolith (150 mm), erosion requires water velocities > 0.1 ms^-1. Calculated erosion rates vary from 5x10^-10 ms^-1 to 3.5x 10^-7 ms^-1 for water velocities between 0.1 ms^-1 and 1 ms^-1, and are higher than for equivalent terrestrial channels, largely because the critical shear stress needed to mobilise sediment is lower due to Mars’ gravity. This suggests that sediment will be readily mobilised beneath wet Martian ice masses, making the supply of water the critical limiting factor. Thus, this study will use an ice flow model to reconstruct a more extensive glacier over a candidate esker in the Phlegra Montes of Mars’ northern mid latitudes. Geothermal heat will be varied, along with other glaciological and climatic parameters, to investigate the possible extent of warm-based ice in the region, and to estimate the extent and volume of subglacial meltwater. The modelled meltwater will then be input into the Mars-adapted subglacial water erosion model to explore the impact of water availability and sediment characteristics on the possible extent of sediment erosion. Modelled sediment supply will then be compared with the sediment volume within the candidate esker, reconstructed from a 1 m/pixel digital elevation model, to help constrain the regional glaciological, sedimentological, climatological and geothermal conditions needed for esker formation.

How to cite: Arnold, N., Butcher, F., Gallagher, C., Balme, M., and Conway, S.: Estimating subglacial water discharges needed to form Amazonian-aged mid-latitude eskers on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14816, https://doi.org/10.5194/egusphere-egu23-14816, 2023.

Ice-rich landforms known as Viscos-Flow Features (VFFs) are common in Mars’ mid-latitudes. Glacier-Like Forms (GLFs) are a distinct sub-category of VFFs and appear morphologically similar to terrestrial valley glaciers or rock glaciers. GLFs are thought to be the result of the redistribution of water ice from the Martian poles during periods of high obliquity (>35^o) and the Last Martian Glacial Maximum (LMGM), which ended ~5 Myr. Numerous distinct impact crater morphologies have been observed on these ice-rich terrains. Research has suggested that this variation results from interactions between landform lithologies and surface evolution through depositional and erosional processes. We investigated impact crater quantities and morphologies on 100 GLFs with large surface areas, with the aim of determining Crater Retention Ages (CRAs) for the landforms and exploring the relationships between crater morphology variation and relative surface ages.

Our results show GLF ages vary across Mars, with various surface retention ages and crater morphologies populations. There are populations of GLFs with young CRAs (<20 Ma), particularly in the southern hemisphere, suggesting recent glaciation could have been more favourable in the southern mid-latitudes. Our results suggest several scenarios for GLFs across Mars. (1) That some GLFs have the potential to be very young, having perhaps formed in the last few million years during the LMGM. (2) That some GLFs may have formed before the LMGM (>20Ma) but have high resurfacing rates, partially removing their impact records. (3) That some GLFs formed long before the LMGM and have medium to very low resurfacing rates. These GLFs have surfaces with greater quantities and morphological variation of craters. Consequently, they also appear to record more resurfacing events and have more comprehensive CRA ranges. The low resurfacing rates suggest that these GLFs have not been in favourable depositional environments for an extended period and are possibly in low erosional settings. The study hints that while high Martian obliquity periods can favour glaciation, material accumulation, and resurfacing events, this occurs within local geographical constraints and that not all periods of glaciation are favourable to all GLFs across Mars.

How to cite: Driver, G., El-Maarry, M. R., Hubbard, B., and Brough, S.: Large Area Glacier-Like Forms on Mars: Insights from Impact Crater Morphologies and Crater Retention Ages, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15877, https://doi.org/10.5194/egusphere-egu23-15877, 2023.

In this work, we show the first achievement of inferring the electron temperature in ionospheric conditions from synthetic data using fixed-bias Langmuir probes operating in the electron saturation region. This was done using machine learning, as well as by altering the probe geometry. The electron temperature is inferred at the same rate as the currents are sampled by the probes. For inferring the electron temperature along with the electron density and the floating potential, a minimum number of three probes is required. Furthermore does one probe geometry need to be distinct from the other two, since otherwise the probe setup may be insensitive to temperature. This can be achieved by having either one shorter probe or a probe of a different geometry, e.g. two longer and a shorter cylindrical probe or two cylindrical probes and a spherical probe. We use synthetic plasma parameter data and calculate the synthetic collected probe currents to train a neural network (using TensorFlow) and verify the results with a test set as well as with data from the International Reference Ionosphere (IRI) model. A table with computed currents collected by a spherical probe by Laframboise was extended to calculate currents of the synthetic plasma parameters for high eta values (eta >25) to cover a large altitude range (100-500 km, within Earth's ionosphere). The extrapolated values were benchmarked with Particle-in-Cell simulations. Finally, we evaluate the robustness and errors of different probe setups that can be used to infer the electron temperature. As the inferred temperatures are compared to results from the International Reference Ionosphere model, we verify the validity of the inferred temperature in altitudes ranging from about 100-500 km. We show that electron temperature inference from different combinations of spherical and cylindrical probes - three cylindrical probes, three spherical probes, four cylindrical and a spherical probe - can be achieved. Even minor changes in the probe sizing enable the temperature inference and result in root mean square relative errors (RMSRE) between inferred and ground truth data of under 3%. With further optimizations, the RMSRE can even be decreased to under 1%. When limiting the temperature inference to 120-450 km altitude an RMSRE of under 0.7% is achieved for all probe setups. In future, the multi-needle Langmuir Probe (m-NLP) instrument dimensions can be adapted for higher temperature inference accuracy.

How to cite: Enengl, F., Marholm, S., Adhikari, S., Marchand, R., and Miloch, W. J.: Electron Temperature Inference from Fixed Bias Langmuir Probes Set-Ups in Ionospheric Conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-542, https://doi.org/10.5194/egusphere-egu23-542, 2023.

Active-region emergence on the Sun shows a degree of clumpiness in both space and time. At a given time, multiple active regions can be seen in what is called active-region- or sunspot-group nests. This tendency also increases the potential to produce large flares and associated CMEs. In the literature, the nesting tendency of active regions is reported in the range of 30-50 per cent, but no statistically robust and ML-based approaches exist so far. Quantifying the nesting degree along an activity cycle and determining its spatial and temporal scales are important to investigate the processes that cause this phenomenon. 

In this study, we estimate the latitudinal and longitudinal extents of active region nesting using both continuum and magnetogram data, using SDO/HMI synoptic magnetograms and Kislovodsk Mountain Astronomical Station (KMAS) sunspot group data. We carry out kernel density estimation (Fig. 1) and unsupervised ML techniques (e.g., DBSCAN and Gaussian mixtures) in spatial and spatio-temporal domains. Our study reveals trends in the emergence characteristics of sunspot groups on the Sun.

Figure 1: Kernel density estimation with a Gaussian kernel on the time-longitude plane. The dot size indicates sunspot group areas in MSH. 

How to cite: Isik, E., Karapinar, N., and Cankurtaran, S. G.: Unsupervised learning of active-region nesting on the Sun, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-850, https://doi.org/10.5194/egusphere-egu23-850, 2023.

A PCA-NN model for the total electron content (TEC) for the midlatitudinal region (Iberian Peninsula) presented here uses the principal component analysis (PCA) to decompose TEC variations into different modes and to reconstruct/forecast amplitudes of these modes using neural networks (NN) with different sets of space weather parameters as predictors.

Feedforward, convolutional and recurrent NN algorithms are tested with different sets of predictors. The performance of the models is tested on 3.5 years of observational data obtained at the declined phase of the 24^th solar cycle, which allows us to estimate the models’ performance in relation to the solar activity level. The advantages and disadvantages of different NN algorithms are discussed.

How to cite: Morozova, A., Gafeira, R., Barata, T., and Barlyaeva, T.: Different types of PCA-NN model for TEC with space weather parameters as predictors: advantages and disadvantages of different NN algorithms, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2719, https://doi.org/10.5194/egusphere-egu23-2719, 2023.

To understand the solar evolution and effects of solar eruptive events, the Sun is permanently observed by multiple satellite missions. The optically-thin emission of the solar plasma and the limited number of viewpoints make it challenging to reconstruct the geometry and structure of the solar atmosphere; however, this information is the missing link to understand the Sun as it is: a three-dimensional, evolving star. We present a method that enables a complete 3D representation of the uppermost solar layer observed in extreme ultraviolet (EUV) light. We use a deep learning approach for 3D scene representation that accounts for radiative transfer, to map the entire solar atmosphere from three simultaneous observations. We demonstrate that our approach provides unprecedented reconstructions of the solar poles, and directly enables height estimates of coronal structures, solar flux ropes, coronal hole profiles, and coronal mass ejections. We validate the approach using model-generated synthetic EUV images, finding that our method accurately captures the 3D geometry even from a limited number of viewpoints. We quantify uncertainties of our model using an ensemble approach that allows us to estimate the model performance in absence of a ground-truth. Our method enables a novel view of our closest star, and is a breakthrough technology for the efficient use of multi-instrument datasets, which paves the way for future cluster missions.

How to cite: Jarolim, R., Tremblay, B., Munoz-Jaramillo, A., Bintsi, K.-M., Jungbluth, A., Santos, M., Mason, J. P., Sundaresan, S., Downs, C., Caplan, R., and Vourlidas, A.: SuNeRF: AI enables 3D reconstruction of the solar EUV corona, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2756, https://doi.org/10.5194/egusphere-egu23-2756, 2023.

Dynamic interactions between the solar wind and the magnetosphere give rise to dramatic auroral forms that have been instrumental in the ground-based study of magnetospheric dynamics. The general mechanism of aurora types and their large-scale patterns are well-known, but the morphology of small- to meso-scale auroral forms observed in all-sky imagers and their relation to magnetospheric dynamics  and the coupling of the magnetosphere to the upper atmosphere remain in question. Machine learning has the potential to provide answers to these questions, but most existing auroral image data lack the ground-truth labels required for supervised learning and conventional statistical analyses. To mitigate this issue, we propose a novel self-supervised semi-supervised algorithm to automatically label the THEMIS all-sky image database. Specifically, we adapt the self-supervised Simple framework for Contrastive Learning of Representations (SimCLR) algorithm to learn latent representations of THEMIS all-sky images. These representations are finetuned using a small set of manually labeled data from the Oslo Aurora THEMIS (OATH) dataset, after which semi-supervised classification is used to train a classifier, beginning by training on the manually labeled OATH dataset and gradually incorporating the classifier’s most confident predictions on unlabeled data into the training dataset as ground-truth. We demonstrate that (a) classifiers fit to the learned representations of the manually labeled images achieve state–of–the–art performance, improving the classification accuracy by almost 10% over the current benchmark on labeled data; and (b) our model’s learned representations naturally cluster into more clusters than manually assigned categories, suggesting that existing categorizations are coarse and may obscure important connections between auroral types and their drivers. Finally, we introduce AuroraClick, a citizen science project with the goal of manually annotating a large representative sample of THEMIS all-sky images for the validation of our current models and the training of future models.  

How to cite: Johnson, J., Ozturk, D., Connor, H., Hampton, D., Blandin, M., and Keesee, A.: Automatic Classification of THEMIS All-Sky Images via Self-Supervised Semi-Supervised Learning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2897, https://doi.org/10.5194/egusphere-egu23-2897, 2023.

Having precise knowledge of the near-Earth solar wind (SW) and the embedded interplanetary magnetic field (IMF) is of critical importance to space weather operation due to the usage of SW and IMF in almost all magnetospheric and ionospheric models. The most widely used data source, OMNI, propagates SW properties from Lagrangian point L1 to the Earth’s bow shock by estimating the propagation time of the SW. However, the time difference between OMNI timeshifted IMF and the best match-up of IMF can reach ˜15 min. Firstly, we aim to develop an improved statistical algorithm to contribute to the SW propagation delay problem of space weather prediction. The algorithm focuses on matching SW features around the L1 point and upstream of the bow shock by computing the variance, cross-correlation coefficient, the plateau-shaped magnitude index, and the non-dimensional measure of average error index between the measurements at the two locations. The obtained propagation times are then compared to OMNI. Factors that limit the OMNI accuracy are also examined. Secondly, the automatic algorithm allows us to generate large sets of input and target variables using multiple spacecraft pairs at L1 and near-Earth locations to train, validate, and test machine learning models to specify and forecast near-Earth SW conditions. Finally, we offer a machine learning (ML) approach to specify and predict the propagation time from L1 monitors to a given location upstream or at the bow shock and forecast near-Earth SW conditions with the gradient boosting and random forest prediction models in the form of an ensemble of decision trees.

How to cite: Tasnim, S., Zou, Y., Borries, C., Baumann, C., Walsh, B., Khanal, K., O'Brien, C., and Zhang, H.: Estimation and Prediction of Solar Wind Propagation from L1 Point to Earth’s Bow Shock, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3379, https://doi.org/10.5194/egusphere-egu23-3379, 2023.

Abstract: Plasma-sheet bubbles play a major role in the process of magnetotail particle injections. They are defined as fast flows with reduced plasma density or pressure accompanied by magnetic field dipolarization. Typically, we can detect these bubbles from in-situ observations, but subjective uncertainty needs human verification. In this study, we combine three different methods including MINImally RandOm Convolutional KErnel Transform (MINIROCKET), 1D and 2D convolution neural network (CNN) to identify bubbles. The imbalanced training dataset consists of bubble and non-bubble events with a ratio of 1:40 from year 2007 to 2020. The results indicate that the accuracy of the all three models is around 99%, and the precision and recall rates of all three models are above 80% in both the validation and test datasets. The three methods are combined with the intersection set as the minimum set of predictions and the union set as the maximum set. The methods greatly reduce the number of false positives. To identify bubbles in the observations of year 2021, our neural network model is found to be comparably good to the traditional criterial and manual inspections. Using joint machine learning forecasting methods, we can easily and automatically identify bubbles without a priori knowledge like a domain expert.

Keywords: plasma-sheet bubble, multivariate time series classification, sample imbalanced, image identification

How to cite: Xuedong, F. and Jian, Y.: Plasma-Sheet Bubble Identification Using Muitivariate Time Series Classification, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4069, https://doi.org/10.5194/egusphere-egu23-4069, 2023.

Laser altimeters create large amounts of data that often have to be preprocessed and checked before further use. The BepiColombo mission to Mercury is set to arrive in December 2025 and observations with the BepiColombo Laser Altimeter (BELA, (Benkhoff et al., 2010; Thomas et al., 2021)) will start during the following spring. These measurements are planned to be used to derive information about the tides of Mercury (Thor et al., 2020). Careful assessment, selection, and filtering on the raw data is needed to extract the small tidal signal. Until the BELA data becomes available artificial data and records from other missions have to be used to study the data selection strategy. We present our work on MESSENGER Laser Altimeter (MLA, (Cavanaugh et al., 2007)) using a convolutional neural network to sort observations on an orbit by orbit basis into different classes. The already existing neural network (Stenzel and Hilchenbach, 2021; Stenzel, Thor and Hilchenbach, 2021) is tuned and a new test data set is created.

How to cite: Stenzel, O., Maes, L., and Hilchenbach, M.: AI Assisted Data Selection of Laser Altimeter Observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5254, https://doi.org/10.5194/egusphere-egu23-5254, 2023.

One of the main sources of solar wind disturbances are coronal holes which can be identified in extreme ultra-violet (EUV) images of the Sun. Previous research has shown the connection between coronal holes and an increase of the solar wind speed at Earth. The time lag between the appearance of coronal holes on the visible side of the Sun and its effects on Earth is 2-5 days. In this study, a machine learning model predicting the solar wind speed originating from coronal holes is proposed. It is based on the analysis of solar EUV images. A segmentation algorithm is applied to the images in order to identify coronal holes and derive their characteristics (e.g. area, location). We also present a new method to calculate the geoeffective coronal hole area: Instead of specifying in advance a sector of the solar surface in which the area is measured and a lag time between area measurement and the arrival of the solar wind, the specification of this sector and the corresponding delay are formulated as a mathematical optimization problem and included in the machine learning model. This approach facilitates an improvement of the prediction accuracy and also prolongs the prediction horizon, as the solar wind speed can be predicted up to approximately 5 days in advance of the disturbance. Several machine learning model architectures are explored. We also study how the time evolution can be included in the model.

How to cite: Collin, D., Bianco, S., Gallego, G., and Shprits, Y.: Forecasting solar wind speed by machine learning based on coronal hole characteristics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6968, https://doi.org/10.5194/egusphere-egu23-6968, 2023.

The detection and classification of landforms on planetary surfaces is a time-consuming task which deeply relies on expert knowledge. Such a process can be partially automated and optimized in a resource-efficient way using image processing algorithms. By classifying the surface into different landforms, such as volcanic craters, asteroid impacts, dunes, and more, several analyses can be performed, for instance the widely used crater counting age estimation method. In addition, by conducting these analyses, information about the characteristics and properties of a planet can be revealed. One of the major challenges for the implementation of these algorithms is to provide a generalized model. In many cases the generalization error tends to be very large and therefore a satisfactory accuracy on the test data set cannot be accomplished. This prevents reliable evaluation of new unseen data. In this work, a multi-class image segmentation algorithm is presented, which is based on a U-net convolutional neural network architecture. U-nets classify each pixel of a given input image and can thus produce segmentation masks for various landforms. Given that enough labeled data is available, such a classifier can replace manual detection and classification, thereby saving resources by providing a fast method for landform detection.

How to cite: Auer-Welsbach, F., Windisch, A., and Nodjoumi, G.: Landform detection on Mars using image segmentation with a u-net convolutional neural network architecture, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7529, https://doi.org/10.5194/egusphere-egu23-7529, 2023.

Deep-learning methods are of interest for the analysis of imagery and digital elevation models from Mars orbiting satellites. They detect various atmosphere and surface characteristics. For instance, these include dust storms and craters [1,2]. We approach this topic by using the deep-learning-based crater detection algorithm DeepMars2 [3,4]. The algorithm is applied to two digital elevation models (DEMs) of the Mars surface. The DEMs are based on the satellite instruments MOLA/MGS (Mars Orbiter Laser Altimeter/Mars Global Surveyor) and HRSC/MEX (High Resolution Stereo Camera/Mars Express) and have different resolution. Crater detection statistics are compared between both DEMs.

[1] Alshehhi, R., Gebhardt, C. Detection of Martian dust storms using mask regional convolutional neural networks. Prog Earth Planet Sci 9, 4 (2022). https://doi.org/10.1186/s40645-021-00464-1

[2] R. Alshehhi and C. Gebhardt, "Automated Geological Landmarks Detection on Mars Using Deep Domain Adaptation From Lunar High-Resolution Satellite Images," in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 15, pp. 2274-2283, 2022, doi: 10.1109/JSTARS.2022.3156371.

[3] Lee, C. (2019). Automated crater detection on Mars using deep learning. Planetary and Space Science, 170, 16-28. https://doi.org/10.1016/j.pss.2019.03.008

[4] Lee, C. & Hogan, J. (2021). Automated crater detection with human level performance. Computers & Geosciences, 147, 104645. https://doi.org/10.1016/j.cageo.2020.104645

How to cite: AlRiyami, H., Gebhardt, C., and Lee, C.: Comparison study on the deep-learning-based detection of Mars craters, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7761, https://doi.org/10.5194/egusphere-egu23-7761, 2023.

Machine learning models trained to reproduce space mission observations are precious resources to fill gaps of missing data in measurement time series or to perform data forecasting within a reasonable uncertainty degree. The latter option is of particular importance for future space missions that will not host instrumentation dedicated to interplanetary medium parameter monitoring. The future LISA mission for low-frequency gravitational wave detection, for instance, will benefit of particle detectors to measure the galactic cosmic-ray integral flux variations and magnetometers that will allow to monitor the passage of large scale magnetic structures through the three LISA spacecraft as part of a diagnostics subsystem. Unfortunately, no instruments dedicated to solar wind speed measurements will be present on board the spacecraft constellation. Moreover, LISA, scheduled to launch in 2035, will trail Earth on the ecliptic at 50 million km distance, far from the orbits of other space missions dedicated to the interplanetary medium monitoring.

Based on precious lessons learned with LISA Pathfinder, the ESA LISA precursor mission, about the correlation between galactic cosmic-ray flux short-term variations and solar wind speed increases, we built a machine learning ensemble model able to reconstruct the solar wind trend only on the basis of contemporaneous and preceding observations of galactic cosmic-ray flux variations. Details about the model creation and performance will be presented, together with a description of the underlying data set, weak predictors and training phase. Advantages and limitations will be discussed, showing that the model performance may be enhanced by providing interplanetary magnetic field intensity observations as additional input data, with the goal of providing the LISA mission with an effective solar wind speed predictive tool.

How to cite: Sabbatini, F. and Grimani, C.: Machine learning ensemble models for solar wind speed prediction, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7941, https://doi.org/10.5194/egusphere-egu23-7941, 2023.

As is known, neural networks can universally approximate any complex functions. This ground truth naturally makes it a suitable candidate for solution representation of complex partial differential equation (PDE) governed. For planetary magnetic field modelling problem, spherical harmonic functions are most used as standard modelling method. Spherical harmonic method requires globally nearly uniformly distributed observations. Meanwhile this method has quite limited ability for conducting regional field modelling. Instead, neural networks have great potential to deal with global or regional modelling problems. In this work, we thoroughly investigate the representative ability of neural networks for magnetic field modelling problem at global and regional scale, and concentrate on a specific neural network, that is physics-informed neural networks (PINNs) for implementation. PINNs makes it easier to incorporate different kinds of informed physics within a uniform optimization framework. Through synthetic model tests and partial mathematical proof, we showcase the importance of employing natural boundary condition, Laplace equation constraint and Poisson equation constraint at suitable collocation points for a reasonable and accurate magnetic field representation and introduce the detailed scheme for implementation. Finally, we use newly released Juno mission measurements, and present a global PINNs model for Jupiter's magnetic field, and a regional PINNs model for Great Blue Spot (GBS) region. Comparison with spherical harmonic model has been conducted to evaluate the correctness and flexibility of PINNs models.

How to cite: Chen, L., Livermore, P., Wu, L., de Ridder, S., and Zhang, C.: Modelling Jupiter's global and regional magnetic fields using physics-informed neural networks, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8430, https://doi.org/10.5194/egusphere-egu23-8430, 2023.

To accurately predict potential future impacts with the Earth, it is crucial to continuously examine the area around it for Near Earth Objects (NEOs) and particularly Near Earth Asteroids (NEAs). Large data sets of astronomical images must be analyzed in order to accomplish this task. NEARBY [1] offers such a processing and analysis platform based on Cloud computing. Despite the fact that this method is automated, the results are validated by human observers after potential asteroids have been identified from the raw data. It is crucial that the amount of candidate objects does not outweigh the available human resources. We believe we can maximize the advantages of having access to enormous amounts of data in the field of astronomy by combining artificial intelligence with the use of high-performance distributed processing infrastructures like Cloud-based solutions. This research is carried out as part of the CERES project which aims to design and put into practice a software solution that can classify objects found in astronomical images. The objective is to identify and recognize asteroids. We use machine learning techniques to develop an asteroid classification model in order to achieve this goal. It is essential to reduce the number of false negative findings. The major objective of the current paper is to assess how well deep CNNs perform when it comes to categorizing astronomical objects, particularly asteroids. We will compare the outcomes of several of the most well-known deep convolutional neural networks (CNNs), including InceptionV3, Xception, InceptionResNetV2, and ResNet152V2. These cutting-edge classification CNNs are used to investigate the best approach to this specific classification challenge, either through full-training or through fine-tuning.

Acknowledgment: This work was partially supported by a grant of the Romanian Ministry of Education and Research, CCCDI - UEFISCDI, project number PN-III-P2-2.1-PED-2019-0796, within PNCDI III. This research was partially supported by the project 38 PFE in the frame of the programme PDI-PFE-CDI 2021.

References:

1. Bacu, V., Sabou, A., Stefanut, T., Gorgan, D., Vaduvescu, O., NEARBY platform for detecting asteroids in astronomical images using cloud-based containerized applications, 2018 IEEE 14th International Conference on Intelligent Computer Communication and Processing (ICCP), pp. 371-376

How to cite: Bacu, V.: Software solution for detecting asteroids using machine learning techniques, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8676, https://doi.org/10.5194/egusphere-egu23-8676, 2023.

To monitor the results of our instrument on a daily basis, we create a series of daily plots that are generated in an automated fashion.  In our case, we are creating two plot types for four spacecraft for five different species.  Unfortunately, due to circumstances beyond our control (primarily network and system issues), plots were failing and if not monitored daily, they were unavailable when finally needed.  

To solve this problem, we investigated using Computer Vision (OpenCV) to validate our generation of daily plots.  It was surprisingly easy and more advantageous than trying to either monitor it daily or more simplistic methods.  By using the cloud, we were able to improve throughput as well.  Future work would be to use Computer Vision to analyze the data within the plots for actual scientific study.

How to cite: Mukherjee, J.: Using Artificial Intelligence/Computer Vision for Automated Plot Validation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8946, https://doi.org/10.5194/egusphere-egu23-8946, 2023.

Coronal mass ejections (CMEs) are one of the most violent solar eruptions, which can burst out large amounts of magnetized plasma with speeds up to thousands of kilometers per second. When it reaches the Earth, a CME can cause geomagnetic storm, affecting aviation safety, satellite operations, communications systems and power facilities. Therefore, fast and accurate prediction of CME arrival time is crucial for avoiding severe damaging effects and reducing economic losses. The initial morphology and kinematics of a CME in the corona can be observed by the coronagraphs equipped on the Solar and Heliospheric Observatory (SOHO), so that the coronagraphs should be useful to predict the CME arrival times. In this study, convolutional neural network (CNN) is used to obtain the features of SOHO/LASCO coronagraph pictures related to the CME transit time, and establish a model capable of predicting the CME arrival time. The influence of different hyperparameters of CNN on the prediction results is studied. Further, we add a physical information constraint of the initial velocities of CME to the basic CNN outputs, and found that smaller prediction errors can be obtained. 

How to cite: Yang, Y., Shen, F., Li, Y., and Lin, R.: Predicting the 1 AU Arrival Time of Coronal Mass Ejections Based on Convolutional Neural Network, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10654, https://doi.org/10.5194/egusphere-egu23-10654, 2023.

Solar eruptive events are complex phenomena, which most often include solar flares, filament eruptions, coronal mass ejections (CMEs), and CME-driven shock waves. CME-driven shocks in the corona and interplanetary space are considered to be the main producer of solar energetic particles (SEPs). A number of fundamental questions remain about how SEPs are produced. Current understanding points to CME-driven shocks and compressions in the solar corona.

A CME kinematics shows three phases - an initial rising phase (weakly accelerated motion), an impulsive phase and a residual propagation phase with constant or decreasing speed.

Despite significant amount of data available from ground-based (COSMO K-Cor, LOFAR) and remote instruments onboard of heliospheric space missions (SDO AIA, SOHO), processing of the data still requires noticeable effort. Most algorithms currently used in solar feature detection and tracking are known for their limited applicability and complexity of their processing chains, while usage of data-driven approaches for tracking of CME-related phenomena is currently limited due to insufficiency of training sets.

Recently (Stepanyuk et.al, J. Space Weather Space Clim. Vol 12, 20(2022)), we have demonstrated the method and the software(https://gitlab.com/iahelio/mosaiics/wavetrack) for smart characterization and tracking of solar eruptive features based on the a-trous wavelet decomposition technique, intensity rankings and a set of filtering techniques. In this work we use Wavetrack to generate training sets for data-driven feature extraction and characterization. We utilize U-Net, a fully convolutional network which training strategy relies on the strong use of data augmentation to use the available annotated samples more efficiently. U-NET can be trained end-to-end from a very limited set of images, while feature engineering allows to improve this approach even further by expanding available training sets.

Here we present pre-trained models and demonstrate data-driven characterization and tracking of solar eruptive features on a set of CME-events.

How to cite: Stepanyuk, O. and Kozarev, K.: Advanced Multi-Instrument and Multi-Wavelength Image Processing and Feature Tracking for Remote CME Characterization with Convolutional Neural Network, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10705, https://doi.org/10.5194/egusphere-egu23-10705, 2023.

We present the analysis of a 2.06 Ga apatite crystal obtained from an ultramafic phoscorite rock from the Phalaborwa Complex (Limpopo Province, South Africa) [1]. A space-prototype laser ablation ionisation mass spectrometer (LIMS) [2,3] was used to study the chemical composition of the sample. Mass spectra were recorded from a sample area of 0.6x0.6 mm², with a spatial resolution of 30 μm and sub-micrometre depth resolution.

Apatite is a calcium phosphate mineral expressed by the chemical stoichiometric formula [Ca₅(PO₄)₃(F, Cl, OH)]. The halogen site, occupied by F, Cl, and OH, corresponds to an isomorpous series with fluor-, chlor- and hydroxyl-apatite end members, respectively. Apatite, being an accessory mineral in igneous and other rocks, commonly contains a range of other elements that do not fit well into the major rock forming minerals, such as rare earth elements (REE). These are suitable targets for investigating physical and chemical conditions in igneous rocks and the volatile evolution of magmas.

The analysis of the spectra recorded with our LIMS system for the abundances of the elements of interest at each location were performed in two steps. First, the abundances of each element across the sampled area were compiled in element maps. And second, an unsupervised machine learning algorithm based on clustering and network analysis was applied to the data set of analysed mass spectra to separate it into groups of distinct chemical composition. Subsequently, a more detailed analysis was conducted on each of the recovered groups to assign the corresponding mineral. In addition to the group of spectra belonging to apatite, which was assigned to fluorapatite, other minerals were identified, amongst others olivine. This method yields an unsupervised approach to identify different mineralogical entities present within a sample. This network analysis method was previously applied to a 1.88 Ga Gunflint sample (Ontario, Canada) to separate spectra recorded from the host (chert) from spectra containing signatures of organic matter from fossilized microbes [4].

Given that the data were recorded using a miniature mass spectrometer designed for space flight, this analysis demonstrates the analytical capabilities of our LIMS system that could be achieved in-situ on other planetary bodies in our Solar System, for example on the Moon or on Mars. The current performance of this miniature LIMS instrument to study the chemical composition of apatite is sufficiently high to measure volatiles (H, F, Cl) and nearly all relevant mineral and partially trace elements (Na, C, Mg, Si, S, K, Mn, Fe, Sr, Ba), including REE (La, Ce, Pr, Sm) which allows for a systematic quantitative analysis of their distribution.

[1] Tulej, M. et al., 2022, https://doi.org/10.3390/universe8080410.

[2] Riedo, A. et al., 2012, https://doi.org/10.1002/jms.3104.

[3] Tulej, M. et al., 2021, https://doi.org/10.3390/app11062562.

[4] Lukmanov, R.A. et al., 2022, https://doi.org/10.3389/frspt.2022.718943

How to cite: Gruchola, S., Tulej, M., Keresztes Schmidt, P., Lukmanov, R., Riedo, A., and Wurz, P.: Composition Analysis of an Apatite Crystal using a Space-Prototype Mass Spectrometric Instrument and Machine Learning for Unsupervised Mineralogical Phase Detection, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11898, https://doi.org/10.5194/egusphere-egu23-11898, 2023.

The origin of cold materials identified by different criteria is unclear. They are highly suspected to be the erupted prominence. However, some cold materials defined by charge depletion exist in both solar wind and ICMEs. Recently, solar observations show failed prominence eruption in CMEs that it did not propagate into the interplanetary space. Besides, the related prominence eruptions of the earth-directed ICMEs at 1 au are difficult to identify before the launch of STEREO mission. This work uses Random Forest (RF) that is an interpretable classifier of supervised machine learning to study the distinct signatures of prominence cold materials (PCs) compared to quiet solar wind (SW) and ICMEs. 12 parameters measured by ACE at 1 au are used in this study, which are proton moments, magnetic field component Bz, He/H, He/O, Fe/O, mean charge of oxygen and carbon, C⁶⁺/C⁵, C⁶⁺/C⁴⁺, and O⁷⁺/O⁶⁺. According to the returned weights from RF classifier and the training accuracy from one black box classifier, the most important in situ signatures of PCs are obtained. Next, the trained RF classifier is used to check the category of the origin-unknown cold materials in ICMEs. The results show that most of the cold materials are from prominence, but 2 of them are possibly from quiet solar wind. The most distinct signatures of PCs are lower charges of C and O, proton temperature, and He/O. This work provides quantitative evidence for the charges of C and O being most effective solid criteria. Considering the obvious overlaps on key parameters between SW, ICMEs, and PCs, multi-parameter classifier of machine learning show an advantage in separating them than solid criteria.

How to cite: Meng, S., Yao, S., and Cheng, Z.: Key Signatures of Prominence Materials and Category of Unknown-origin Cold Materials identified by Machine Learning Classifier, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12354, https://doi.org/10.5194/egusphere-egu23-12354, 2023.

Pits, or pit craters, are roughly circular depressions found in planetary surfaces which are generally formed through gravitational collapse. Pits will be primary targets for future space exploration and habitability for their presence on most rocky Solar System surfaces and their potential to be entrances to sub-surface cavities. This is particularly true on the Moon and Mars where future astronauts will also be exposed to high radiation dosages whilst on the surface. However, since pits are rarely found to have corresponding high-resolution elevation data, tools are required for approximating their depths in order to find those which are the ideal candidates for exploration and habitation.

We develop a tool that automatically calculates a pit’s apparent depth – the depth at the edge of its shadow - by measuring the shadow’s width as it appears in satellite imagery. The tool can produce a profile of the apparent depth along the entire length of the shadow, using just one cropped single- or multi-band image of a pit. Thus, allowing for the search for possible cave entrances to continue where altimetry or stereo image data is not available. Shadows are automatically extracted using k-means clustering with silhouette analysis for automatic cluster validation. We will present the results of testing the shadow extraction upon shadow-labelled Mars Reconnaissance Orbiter HiRISE imagery of Martian pits, as well as the findings of applying the tool to HiRISE images of Atypical Pit Craters (APCs) from the Mars Global Cave Candidate Catalog (MGC³) [1]. We will also present preliminary results of applying our tool to Lunar Reconnaissance Orbiter Narrow Angle Camera data taken of Lunar pits catalogued in the Lunar Pit Atlas [2].

[1] – Cushing et al. (2015). Atypical pit craters on Mars: New insights from THEMIS, CTX, and HiRISE observations, Journal of Geophysical Research: Planets, 120, 1023–1043

[2] – Wagner & Robinson (2021). Occurrence and Origin of Lunar Pits: Observations from a New Catalog, in 52nd Lunar and Planetary Science Conference, Lunar and Planetary Science Conference, p. 2530

How to cite: Le Corre, D., Mason, N., Bernard-Salas, J., Cox, N., and Mary, D.: Automatically Calculating Depths of Martian and Lunar Pits with Satellite Imagery, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14927, https://doi.org/10.5194/egusphere-egu23-14927, 2023.

The BepiColombo mission will arrive at Mercury in 2025. It consists of two spacecraft, which both have a magnetometer on board. One of the science objectives of these instruments is to study the structure of Mercury’s magnetosphere and its dynamical interaction with the solar wind. To study this statistically, a large dataset of observations of the magnetopause (the magnetosphere’s outer boundary) is needed. However, identifying such magnetopause crossings in magnetic field data requires visual inspection by humans with expert knowledge and as such is a very time consuming process. We therefore design an algorithm to automatically detect the Hermean magnetopause in magnetometer time series data, making use of a convolutional neural network.

Since no BepiColombo data (in orbit) is available yet, we train the network on MESSENGER magnetometer data. However, we formulate the problem and design the architecture of the network in such a way that the algorithm should be easily transferable to BepiColombo magnetometer data, avoiding the possible impact of any instrumental particularities or orbital biases.

The goal is to have a neural network which is directly applicable to BepiColombo magnetometer data, as soon as the observations start and without any further training, thereby eliminating the necessity of manually creating a new dataset of BepiColombo magnetopause crossings.

How to cite: Maes, L., Fraenz, M., and Heyner, D.: Detecting the magnetopause of Mercury by neural network — using MESSENGER data to train for BepiColombo., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15160, https://doi.org/10.5194/egusphere-egu23-15160, 2023.

Aiming to unravel the astrobiology of Mars, the Perseverance mission came with a lot of unknowns. With the surface level knowledge that we have already known, The High Resolution Imaging Science Experiment (HiRISE) can already determine the observation or experimental sites through the images generated from the orbiter. Although the resolution is high, with the power of a 1-meter-size object determinator, we can always expect so much more from the ground-level observation.

The Mars Perseverance rover is equipped with a pair of Mastcam-Z set cameras that are equipped in a manner to simulate the human eye for depth determination in image processing. The instruments can process stereo colour images of the ground level. These images can be used to make detailed maps of the Mars surface scenery at ground level with high precision.

Building and analyzing these images can take days to process on Earth manually. But if we utilise machine learning tools and onsite computation, it might save a lot of time for the mission. The current model used in the Mars Perseverance is the AutoNav Mark 4 with a lot of tasks, including spacecraft positioning, in-flight orbit determination, target tracking, and ephemeris calculations. All those might be computationally expensive to process. Therefore, the aim of this research is to develop a simple algorithm to do object and slope determinations to feed into an autonomous path determination process. The data fed into the algorithm are panoramic images captured by the MastCam-Z mounted on Mars Perseverance.

How to cite: Swida, O. B., Foing, B., and Vleugels, C.: Mars Perseverance Panoramic Image for Self-Determination Mission Algorithm, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16941, https://doi.org/10.5194/egusphere-egu23-16941, 2023.

Large parts of the Martian surface have been imaged with orbiters. The High Resolution Imaging Science Experiment (HiRISE) can be used to build Digital Terrain Models (DTMs) of Mars with high horizontal and vertical resolution – distinguishing metre-size objects with a vertical error of tens of centimetres – and interpret the geologic history of a site. These maps may aid in rover landing site selection and finding science targets for these missions. However, rover-based imaging ultimately brings the most detailed view of a site and provides ‘ground-truth’ data to orbital observations on much smaller scales. Studying the differences between geologic interpretations from larger scale orbital observations and smaller scale rover images helps understand the limits of orbital maps and the added value of rover observations. We compare remote sensing data from orbit with rover panoramic camera data. The validity of geologic interpretations derived from orbital image data (such as HiRISE) in Jezero Crater is examined with ground-based, publicly available data from Mastcam-Z on the Mars 2020 Perseverance rover. Mastcam-Z can provide stereo colour images of the scene around the rover. 

The rover is currently in its Delta Campaign after landing at the Octavia E. Butler site and its subsequent trip to the Séítah formation, indicated in the figure below which shows Perseverance’s traverse near the western delta of Jezero crater (the basemap is a HiRISE DTM overlaid on a Context Camera mosaic produced by The Murray Lab).  Along the way, it has imaged the Séítah and Máaz formations and outcrops of the western delta formation. These units are expected to be volcanic (Séítah and Máaz) and deltaic (western delta) deposits. We can use the Mastcam-Z images made along the traverse to test what geologic interpretations we can reliably infer from orbital data.

How to cite: Vleugels, C., Foing, B., and Swida, O.: A comparison of Perseverance rover and HiRISE data: siteinterpretations in Jezero Crater, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-320, https://doi.org/10.5194/egusphere-egu23-320, 2023.

We present a cost-efficient borehole tilt sensor that was developed by our group at Dartmouth College to study ice deformation on Jarvis Glacier in Alaska. We first detail the entire sensor development, deployment, and data collection process, along with showcasing successful use cases of our sensors on Jarvis and other glaciers both by our and other geophysical research groups. For our Jarvis work, we installed our tilt sensor system in two boreholes drilled close to the lateral shear margin of Jarvis Glacier and successfully collected over 16 months of uninterrupted borehole deformation data in a harsh polythermal glacial environment. The data included gravity and magnetic measurements that tracked the orientation of the sensors in the borehole as ice flows, and we used the resultant kinematic measurements to compute borehole deformation that provided insights into the ice flow dynamics on polythermal glaciers. Our tilt sensors can house many types of sensors to accommodate different scientific needs (e.g., temperature, pressure, electrical conductivity), and can be adapted for the different glacial thermal regimes and conditions like Athabasca Glacier in Canada, which is a temperate glacier in contrast to Jarvis’ polythermal regime. There remains a high knowledge and financial barrier to entry for borehole geophysics research for both development and procurement of a tilt sensor system, and our goal is to lower this barrier by supporting production efforts of our tilt sensor system for both research and educational needs. With our established sensor development plan and demonstrated success in the field, our group has collaborated with Polar Research Equipment (PRE), a Dartmouth alumni-founded company specializing in the development of polar research tools, to serve as a commercial resource to help support polar researchers during the development and/or production of an effective and cost-efficient (~80% cheaper than commercial versions) tilt sensor and its associated systems.

How to cite: Lee, I., Hawley, R., Collins, D., and Elliott, J.: Improving the Accessibility of Borehole Geophysics: A Cost-Efficient, Highly Modifiable Borehole Tilt Sensor, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1679, https://doi.org/10.5194/egusphere-egu23-1679, 2023.

With MaQuIs we propose a mission to investigate the gravitational field of Mars. Observing the gravitational field over time yields information about the planets tectonic lithoshphere, mass distribution, and composition. Consequently, this mission allows to study static and dynamic processes on and under the surface of Mars, including phenomena such as melting cycles and tectonic activity.

MaQuIs will deploy quantum mechanical means to measure Mars gravitational field with the highest precision yet. In addition, the nature of the proposed instrumentation achieves high sensitivities without needing more complex satellite constellations. As such, MaQuIs follows successful missions for the Earth and Moon, extending the technology to Mars.

In this presentation we will outline the expected scientific merit and explain the underlying technology and planned configuration of the mission.  

How to cite: Woerner, L., Root, B., Bouyer, P., Braxmaier, C., Dirkx, D., Encarnacao, J., Hauber, E., Hussmann, H., Karatekin, O., Koch, A., Kumanchik, L., Migliaccio, F., Reguzzoni, M., Ritter, B., Schilling, M., Schubert, C., Thieulot, C., von Klitzing, W., and Witasse, O.: MaQuIs - Mars Quantum Gravity Mission, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2676, https://doi.org/10.5194/egusphere-egu23-2676, 2023.

One of the challenges in space instrumentation is to measure the energy and 3D angular distribution of charged particles within the limited resources available on planetary missions. Current electrostatic energy analyzers allow the measurement of the energy and angular distribution of charged particles around a 2D viewing plane.

Since most planetary probes are three-axis stabilized, electrostatic scanning deflectors are needed to provide the 3D distribution of charged particles using a minimum of two sensors. However, deflections up to +/- 90° cannot be achieved at high energy (above 10-15 keV) while higher energy accelerated particles play a key role in the dynamics of planetary magnetospheres. In addition, electrons and positive ions have to be measured with dedicated sensors which increases the complexity of plasma payloads and of their accommodation on planetary platforms.

We introduce a novel instrument design, that would allow measurement of the energy spectrum and 3D angular distribution of charged particles on three-axis stabilized platforms without using scanning deflectors. The design is possible using new electrostatic geometries and the capability of additive manufacturing technology. An innovative and compact ion/electron detection system is used to simultaneously observe both type of particles with a single sensor.

 We show that we reach the performance of current reference designs while having a true 3D field of view and significantly reducing the payload needs. With a mass budget of 2 kg, our combined electron/ion instrument fits the requirements to fly aboard small satellites. It would significantly reduce the size and cost of the platform and may open new perspectives for planetary exploration by a fleet of micro/nano-satellites.

How to cite: Hénaff, G., Berthomier, M., Frédéric, L., Jean-Denis, T., Gabriel, D., and Sylvain, P.: Development of a 3D-printed ion-electron plasma spectrometer with an hemispheric field of view for microsats and planetary missions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2838, https://doi.org/10.5194/egusphere-egu23-2838, 2023.

NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) imaging spectrometer was launched to the International Space Station (ISS) on the 14^th of July 2022.  EMIT measures the spectral range from 380 to 2500 nm with 285 contiguous spectral channels with 60 m spatial sampling and an 80 km swath.  The EMIT imaging spectrometer is optically fast at F/1.8 to deliver high signal-to-noise ratio observations.  Novel methods are used for on-orbit calibration, dark signal measurement, and geolocation.  The EMIT measurement characteristics and processing results through calibration, atmospheric corrections, and surface mineralogy retrievals are reported.  The EMIT science team will use these new comprehensive observations of surface mineralogy across the Earth’s arid land dust source regions to update the initial conditions of Earth System Models to understand and reduce uncertainties in mineral dust radiative forcing at the regional and global scale now and in the future.  EMIT’s measurements, products, and results with be available to other investigators for the broad set of science and applications they enable through the NASA Land Processes Data Active Archive Center.  The connection between EMIT, Carbon Plume Mapper, the Mapping Imaging Spectrometer for Europa, and the High-resolution Volatiles and Minerals Moon Mapper on Lunar Trailblazer is also described.

How to cite: Green, R.: Imaging Spectroscopy Observations from NASA’s Earth Surface Mineral Dust Source Investigation launched in 2022 and Connections to Imaging Spectrometers for Greenhouse Gas Measurement, Europa, the Moon, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4510, https://doi.org/10.5194/egusphere-egu23-4510, 2023.

Atmospheric erosion plays a significant role in the long-term evolution of planetary atmospheres, and therefore on the development and sustainability of habitable conditions. Atmospheric escape varies over time, due to changes in planetary conditions and the evolution of the Sun. In the case of a magnetized planet like Earth, the dominant scavenging mechanisms are polar wind and polar cusp escape. Both processes are sensitive to the ion supply from the atmosphere, which depends on the solar EUV radiation and the composition of the neutral atmosphere. Moreover, they are modulated by the coupling between the solar wind and the ionosphere, which depends on the solar wind dynamic pressure and the planetary magnetic moment.

We developed a semi-empirical model of atmospheric loss to extrapolate from current measurements of oxygen escape from Earth to past conditions. This model takes into account the variations of the solar EUV/UV flux, the solar wind dynamic pressure, and the Earth’s magnetic moment. In this study, we identify the main factors and processes that control oxygen escape from Earth, considering present-day atmospheric conditions. We constrain the variation of the oxygen loss rate over time and estimate the total oxygen loss during the last ~2 billion years.

How to cite: Alonso Tagle, M. L., Maggiolo, R., Gunell, H., De Keyser, J., Cessateur, G., Lapenta, G., Pierrard, V., and Vandaele, A. C.: Evolution of the oxygen escape from Earth over geological time scales, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7046, https://doi.org/10.5194/egusphere-egu23-7046, 2023.

Silicon detectors are widely used for analyses of particles/radiation in space. They show a good response for a wide spectrum of different particles. Via construction of an appropriate shielding, one can select and analyze only a single sort of particles/their energy and suppress detection of particles of all other kinds. It is difficult to find a good solution for shielding only experimentally. A modeling software such as Geant4 allows us to find a solution for the shielding. This software calculates interaction of particles with shielding or detector and the resulting energy deposition.

The current work is based on modeling of aluminum shielding of the RAPID/IES instrument on board of four Cluster spacecrafts. Since 2000 Cluster mission encounters the Earth's radiation belts and measures energetic electrons among other particles, waves and electromagnetic fields. Accurate modeling using Geant4 allows us to filter unwanted particles out of the result and possibly remove some artifacts in space.

The Geant4 code calculates an attenuation of radiation. Preliminary this software does not calculate electrical signal. There is, however, a possibility to extend the code and add other functionalities. We are exploring possibilities to include signal processing in the Geant4 code for the detector, analog and digital processing units.

How to cite: Rashev, M.: On modeling of silicon detector for space applications using Geant4, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7363, https://doi.org/10.5194/egusphere-egu23-7363, 2023.

Importance of solar wind monitoring for space weather applications increases with expansion of power networks and oils or gas pipelines to larger geomagnetic latitudes and development of new communication networks. Instruments based on Faraday cups are an ideal solution for these purposes because they are robust and their light weight and low power consumption facilitate their applications for a small spacecraft. Another important feature of Faraday cups is their capability of detection of impacts of interplanetary dust. Such instruments are currently a part of two planned ESA missions that will be briefly introduced. In the core of contribution, we describe the preliminary instrument design and concentrate on most important technical aspects of their development including a computer modeling of the most important parts of detectors. Among others, we present the effects of the grid geometry on the detector capability to determine the plasma velocity vector and temperature and search for optimum detector configuration for small spacecraft missions. We also discuss the data strategy allowing maximum scientific income with limited spacecraft telemetry.

How to cite: Kononov, O., Pavlů, J., Ďurovcová, T., Šafránková, J., Němeček, Z., and Přech, L.: Faraday cup instruments for solar wind and interplanetary dust monitoring, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7966, https://doi.org/10.5194/egusphere-egu23-7966, 2023.

Introduction

The scientific exploration of planetary bodies is enhanced using spectral indexes, and specific band combinations/operations that allow the interpretation of the compositional properties of planetary surfaces. The best hyperspectral sensor for the study of the Moon is M³ onboard Chandrayan-1 (Pieters et al., 2008), it has 86 channels, and covers the range between 450 to 3000 nm, a region that shows the main properties of the rock-forming minerals of the Moon. Although the data of M³ has been widely used with different techniques, there is no unified set of spectral indexes for this instrument, and the ones defined are usually produced in proprietary software. In this work, we compiled spectral indexes from several sources and recreated them in python.

Methods

We compiled spectral indexes from the literature, namely the ones defined by Zambon et al. (2020), Bretzfelder et al. (2020), and Horgan et al. (2014). Before applying the indexes, an M³ cube was processed in ISIS3 (Laura et al., 2022) and filtered in python to reduce the noise. Subsequently, the spectral indexes were replicated according to the procedures described by the authors and compared with the original results. Most of the process was done with common scientific libraries such as rioxarray (Guillies, 2013), OpenCV (Bradski, 2000), specutils (Earl et al., 2022), and NumPy (Harris et al., 2020).

Results

We were able to reproduce fourteen indexes with high fidelity. All of them are formulated to highlight the spectral features around the absorptions in 1000 nm and 2000 nm, which are the location with the major expressions from olivine and pyroxenes. Comparing our results with the ones in the literature, we found that the color ramps are similar in both results and that the surface features showcased in both cases are consistent with each other and their known compositions.

Discussion and conclusions

Small differences between the original indexes and the ones recreated here are expected, due to variations in the internal methods across libraries, the different ways of preprocessing and filtering, and the quality of the original cubes. Further comparison and validation of the procedures is planned.

Nevertheless, we believe that the results are consistent enough to be used as scientific inputs, thus providing an open-source alternative for the analysis of spectral indexes of the surface of the Moon. This work is in progress, and the code is going to be available via EuroPlanet GitHub organization (https://github.com/europlanet-gmap), as well as in the Space Browser of the EXPLORE platform (https://explore-platform.eu/space-browser).

Acknowledgments

This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 101004214.

References

Bradski, G. (2000). The OpenCV Library.

Bretzfelder et al., (2020). Identification of Potential Mantle Rocks Around the Lunar Imbrium Basin.

Earl et al., (2022). astropy/specutils: V1.9.1 

Gillies, S. & others. (2013). Rasterio: Geospatial raster I/O for Python programmers. 

Harris et al., (2020). Array programming with NumPy.

Horgan et al., (2014). Near-infrared spectra of ferrous mineral mixtures and methods for their identification in planetary surface spectra.

Laura et al., (2022). Integrated Software for Imagers and Spectrometers 

Zambon et al., (2020). Spectral Index and RGB maps.

How to cite: Suarez Valencia, J. E., Pio Rosi, A., and Nodjourmi, G.: Formulation of spectral indexes from M3 cubes for lunar mineral exploration using python, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8161, https://doi.org/10.5194/egusphere-egu23-8161, 2023.

Strofio is a neutral mass spectrometer designed to measure the chemical composition of Mercury’s exosphere. Neutral species enter the instrument through one of two inlets before they are ionized via electron impact. The product ions are then guided by dozens of individually programmed electrodes toward the detector. A rotating electric field determines the time-of-flight (TOF) of each particle before they collide with a microchannel plate (MCP). Upon launch, one of the system’s electrodes (D5) suffered an anomaly that disrupted communications between the commanded value and the value reported in telemetry. This particular electrode is responsible for steering the particles into the MCP. Laboratory tests with the engineering model confirm mission requirements are satisfied regardless of the electrode state with the caveat being a reduced first-order mass range; however, second-order manipulation can extend the mass range to pre-anomaly standards. I will present the latest advances we have made in optimizing the instrument in its current state.

How to cite: Schroeder, J., Livi, S., and Allegrini, F.: Strofio: A Status Update, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8918, https://doi.org/10.5194/egusphere-egu23-8918, 2023.

EuroSpaceHub is a project funded by the EIT HEI initiative, led by EIT Manufacturing and Raw Materials. The main goal of the project is fostering collaborative innovation and entrepreneurship in the Space-Tech ecosystem. EuroSpaceHub includes several initiatives; among them is the EuroSpaceHub Academy: an educational programme to train young students, researchers and professionals as Analog Astronauts and Space entrepreneurs.

Thanks to the experience of one of the founding partners of EuroSpaceHub - Lunex EuroMoonMars - students have the opportunity to participate as analog astronauts in various campaigns, which makes them learn with a hands-on approach. Analog missions are both important for carrying out investigations with a view to future Space exploration  and for developing technical scientific knowledge in students. EuroMoonMars has been involved in the organization of these campaigns since 2009, starting at the MDRS (Utah). Other missions were organized at the HISEAS base on the Mauna Loa (Hawaii), in Iceland (CHILL-ICE), in Etna/Vulcano Italy, Atacama Desert (Chile), at the AATC in Poland, ESTEC Netherlands, Eifel Germany and others [1-10]. During analog simulations, students learn to control on-board instruments and to structure their own experiments, collecting data and processing the results efficiently. EuroSpaceHub and Lunex support not only student participation in these missions and their organisation, but also a set of specific trainings under the umbrella of the ESH Academy, complementary to the missions. During the missions, PhD and Master's students can take advantage of special settings and equipment to conduct their investigations, which range from Space and planetary science, instruments, protocols, data analysis,
(biology, psychology, physiology and engineering, to name but a few).

EuroSpaceHub and Lunex are also developing an innovative habitat for analog missions and outreach, ExoSpaceHab Express. Its easy transportation, which is conceived on wheels, makes it a unique contribution in the landscape of existing habitats. Thanks to ExoSpaceHab-X, an increasing number of students will have access to the missions and dedicated training. Also, more and more data will be collected to investigate crews’ reactions in confinement, mission protocols, planning and operations. 

References: [1] Foing, B. et al (2022) LPSC 53, 2042 [2] Foing B. et al (2021) LPSC52, 2502 [3] Musilova M. et al (2020) LPSC51, 2893 [4] Perrier I.R. et al (2021) LPSC52, 2562 [5] Crotti, S. et al (2022) EGU22, 5974 [6] Foing, B. et al (2021) LPSC52, 2502 [7] Heemskerk, M. et al (2021) LPSC52, 2762 [8] Foing, B. et al (Editors, 2011) Astrobiology field Research in Moon/Mars Analogue Environments, Special Issue IJA, 10, vol. 3. 137-305; [9] Foing B. et al. (2011) Field astrobiology research at Moon-Mars analogue site: Instruments and methods, IJA 2011, 10 (3), 141 [10] Foing, B. H. et al, (2017) LPICo2041, 5073 

Acknowledgments: We thank EuroSpaceHub Consortium, collaborators, EIT HEI initiative, EIT Manufacturing and Raw Materials, VilniusTech, Collabwith, International Space University, Universidad Complutense de Madrid, Igor Sikorsky Kyiv Polytechnic Institute, Lunex Foundation and EuroMoonMars. We thank Adriano Autino and Space Renaissance International, all EMMPOL participants and the staff of AATC.

How to cite: Crotti, S., Pascual, J., Foing, B., Kołodziejczyk, A., Reymen, B., Perrier, I. R., Rogers, H., Pavanello, S., Rauch, C. A., De La Torre, G., and Wedler, A.: Training the future Space Entrepreneurs and Astronauts: the experience of the EuroSpaceHub Academy with the Analog Missions for validation of planetary instruments, protocols and techniques, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9318, https://doi.org/10.5194/egusphere-egu23-9318, 2023.

The asteroid (16) Psyche is the target of the NASA Psyche mission, where the magnetometer is one of the three science instruments on board. Its purpose is to prove whether the asteroid formed from the core of a differentiated planetesimal. The magnetometer will measure the magnetic field at different distances from the asteroid in order to detect any remanent magnetization, where a magnetic moment larger than 2×10^14 Am2 could imply that the body once generated a core dynamo, and therefore formed as an igneous differentiation.

The Psyche spacecraft carries two three-axis fluxgate magnetometers mounted on a fixed boom at 2.15m and 1.45m, respectively, which provide redundancy and gradiometer capabilities to compensate for spacecraft-generated magnetic fields. The magnetometers will be powered on early in the initial checkout phase and remain on throughout cruise and orbital operations and producing 50 vectors per second. The in-flight temperature of the magnetometers is expected to span a large range, therefore an extensive calibration program has been carried out in order to characterize the instruments and prove the performance pre-flight.

How to cite: Merayo, J. M. G., Weiss, B. P., Ream, J., Oran, R., Brauer, P., Cochrane, C. J., Cloutier, K. D., Elkins-Tanton, L., Jørgensen, J. L., Maurel, C., Park, R. S., Polanskey, C. A., Pich, M. D. S.-S., Raymond, C. A., Russell, C., Wenkert, D., Wieczorek, M. A., Zuber, M. T., and Webster, K.: The Magnetometer on the Psyche mission, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9912, https://doi.org/10.5194/egusphere-egu23-9912, 2023.

The calibrated data from the Cluster fluxgate magnetometer instruments (FGMs) aboard the four Cluster spacecraft are accessible through the European Space Agency (ESA) Cluster Science Archive (CSA). The FGM team at Imperial College – the PI institute that built and supports operation of the magnetometers – has regularly provided validated data to the CSA since its inception. The calibration and validation pipeline is well established and provides measurements at the highest instrument resolution within an uncertainty as low as 0.1 nT. New methods for magnetic field calibration have been proposed in the many years since Cluster’s commissioning. One of these uses mirror mode waves in the Earth’s magnetosheath to determine the spin-axis offsets of an in-flight magnetometer instrument. The FGM team applied this method to the Cluster instrument data during periods when the spacecraft spend a substantive proportion of their orbits in the magnetosheath, typically May-June and October-November. The offsets determined by this method were compared to those determined by the method already integrated into the pipeline. Good agreement was found between the two methods.

Due to the limitations in resource, the substantial effort that would be required to change calibration methods and re-deliver over 20 years of FGM data, and the potential impact on literature already published, the team would not recommend retroactive integration of the new method into the pipeline. However, the study provides a useful sense check of the pipeline and the data already delivered, as well as the remaining data to be delivered through to the end of the Cluster mission.

How to cite: Alconcel, L.-N., Oddy, T., Brown, P., and Carr, C.: Sense-checking the calibration of the Cluster FGM magnetometer spin-axis offsets using mirror mode waves in the magnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10104, https://doi.org/10.5194/egusphere-egu23-10104, 2023.

We propose a suite of instruments, Botany on The Moon, designed to investigate the feasibility of plant growth on the Moon. Botany is composed of two single-species plant growth modules (Arabidopsis, & radish) plus two environmental monitoring instruments that record (1) direct and scattered sunlight in the photosynthetically active radiation or wavelengths (termed PAR), and (2) level of cosmic radiation and induced lunar neutrons. Together these four investigations contribute to our understanding of how plants can be grown on the Moon.

The core perspective in Botany is that physical experiments are needed to understand plant growth on the Moon. Little is known about plant behavior in reduced (fractional) gravity environments (less than the nominal 1g that occurs on Earth). How biology responds to partial gravity (in combination with radiation effects) remains unexplored.

Botany’s primary science goals can be achieved during the sunlit timeframe of a Lunar Day. However, significantly more data and knowledge is gained by extending the growth duration window to approximately 45 Earth days. Hence, Botany is proposing to take advantage of the CLPS provided Survive-the-Night service.  If the CLPS provider is able to provide power for Botany to survive the night, our secondary science goal to determine the feasibility of transitioning the plants from a normal growth phase (at 22^oC during the sunlit time) to a slow growth phase (at 5^oC during the nighttime), returning to normal growth phase (at 22^oC during the second sunlit time) can be achieved. However, all of Botany’s primary science goals can be achieved during the lunar sunlit timeframe, albeit with the loss of data due to the shorter growth duration. The Botany instrument suite including the LPX plant chambers are designed for a 45 Earth-day mission on the Lunar surface, including surviving the 354 hours of the Lunar night. The Botany on The Moon proposed project has a payload mass of ~ 12kg and estimated cost of ~ $11.5 Million U.S. dollars.

The 20-person Botany payload team is led by a mid-career women scientist and involves a gender diverse science and engineering team at various stages in their career from 10 institutions located within three countries. The Botany team includes NASA ARC, KIPR (a long-term NASA ARC contract organization), SDL, UNC-G (a minority serving institution (MSI)), a Canadian instrument provided by McMaster University, and a science team from various institutions. Our team combines complimentary skills, mission management experience, and expertise in plant science.

How to cite: Smith, H.: Botany on The Moon, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10788, https://doi.org/10.5194/egusphere-egu23-10788, 2023.

The HyTI (Hyperspectral Thermal Imager) mission, funded by NASA’s Earth Science Technology Office InVEST (In-Space Validation of Earth Science Technologies) program, will demonstrate how high spectral and spatial long-wave infrared image data can be acquired from a 6U CubeSat platform. The mission will use a spatially modulated interferometric imaging technique to produce spectro-radiometrically calibrated image cubes, with 25 channels between 8-10.7 microns, at 13 cm^-1 resolution), at a ground sample distance of ~60 m. The HyTI performance model indicates narrow band NEDTs of <0.3 K. The small form factor of HyTI is made possible via the use of a no-moving-parts Fabry-Perot interferometer, and JPL’s cryogenically-cooled HOT-BIRD FPA technology. Launch is scheduled for June 2023. The value of HyTI to Earth scientists will be demonstrated via on-board processing of the raw instrument data to generate L1 and L2 products, with a focus on rapid delivery of data regarding volcanic degassing, and land surface temperature. This presentation will describe the mission and the technology, including the interferometric imaging approach, and how the Cube Sat will support instrument operations and data processing.

How to cite: Wright, R. and the HyTI Team: The HyTI Mission: High Spatial and Spectral Sesolution Imaging from a 6U Cube Satellite, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10917, https://doi.org/10.5194/egusphere-egu23-10917, 2023.

The ESA-JAXA BepiColombo mission is currently en route to Mercury since October 2018. It consists of the ESA Mercury Planetary Orbiter (MPO) and the JAXA Mercury Magnetospheric Orbiter (MMO) spacecraft which, along with the Mercury Transfer Module (MTM), are stacked all together during the seven years’ cruise phase. This long cruise phase is interspersed by nine planetary flybys used to reach Mercury’s orbit capture. In this configuration, most of the MPO instruments located on the nadir side are obstructed by the MTM and cannot observe. Nevertheless, a subset of “side-looking” instruments can be operated in the stacked-spacecraft configuration during the cruise and gather scientific data. These instruments, mostly dedicated to the study of the Hermean environment (magnetic field, solar wind, exosphere), are operated during the planetary flybys as well as for several cruise science observations. Such events are used to test the BepiColombo Science Ground Segment (SGS) operating systems and processes. The SGS develops the Quick-Look Analysis (QLA) tool that will support the rapid analysis of the instruments’ operational and scientific data acquired during the mission science phase observations, starting in 2026. At present, the tool is used to support cruise and flybys operations, in addition to fostering science collaborations between the BepiColombo instrument teams through its data sharing capabilities. We will present the current status and functionalities.

How to cite: Cornet, T., Macfarlane, A., Racero, E., Besse, S., and Martinez, S.: BepiColombo: Operations and Data Analysis through the Quick-Look Analysis (QLA) tool, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11555, https://doi.org/10.5194/egusphere-egu23-11555, 2023.

In response to the problem that ground-based optical monitoring systems cannot monitor near-Earth asteroids which are too close to the Sun on the celestial sphere, we raise a method that tracks and determines the orbit of asteroids by Distant Retrograde Orbit (DRO) platforms with optical monitoring. Through data filtering by visibility analysis and the initial orbit information of the asteroids provided by Jet Propulsion Laboratory (JPL), the asteroids' orbits are determined and compared with the reference orbit. Simulation results show that with a measurement accuracy of two arcseconds and an arc length of three years, the orbit determination accuracy of the DRO platform for near-Earth asteroids can reach tens of kilometers, especially the asteroids with Atira orbits to an accuracy of fewer than ten kilometers. In conclusion, the near-Earth asteroids monitoring systems based on DRO platforms are capable to provide sufficient monitoring effectiveness which enables precise tracking of the target asteroids and forecast of their positions.

How to cite: Yezhi, S.: Near-Earth asteroids orbit determination by DRO space-based optical observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13233, https://doi.org/10.5194/egusphere-egu23-13233, 2023.

Callisto, the outermost of the four Galilean satellites, is identified as a key body to answer present questions about the origin and the formation of the Jovian system. Callisto appears to be the least differentiated and the geologically least evolved of the Galilean satellites, and therefore the one best reflecting the early ages of the Jovian system.

While the ESA JUICE mission plans several flybys of Callisto, an orbiter would allow it to measure geodetic parameters to much higher resolution, as it was suggested by several recent mission proposals,e.g., the Tianwen-4 (China National Space Administration) and MAGIC (Magnetics, Altimetry, Gravity, and Imaging of Callisto) proposals. Recovering parameters such as those describing Callisto’s gravity field, its tidal Love numbers, and its orientation in space would help to significantly constrain Callisto’s interior structure models, including the characterization of a potential subsurface ocean.

We perform a closed-loop simulation of spacecraft tracking, altimetry, and accelerometer data of a high inclination, low altitude orbiter, which we then use for the recovery of its precise orbit and of Callisto’s geodetic parameters. We compare our sensitivity and uncertainty results to previous covariance analyses. We estimate geodetic parameters, such as gravity field, rotation, and orientation parameters and the k2 tidal Love number, based on radio tracking (2-way Doppler) residuals. We consider several ways to mitigate the mismodeling of non-gravitational accelerations, such as using empirical accelerations and pseudo stochastic pulses, and we evaluate the benefits of an on-board accelerometer.

We also investigate the added value of laser altimeter measurements to enable the use of altimetry crossovers to improve orbit determination and gravity-related geodetic parameters, but also to estimate the recovery of surface tidal variations (via the h2 Love number). For our closed-loop analyses, we use both a development version of the Bernese GNSS Software and the open-source pyXover software.

How to cite: Desprats, W., Arnold, D., Bertone, S., Blanc, M., Jäggi, A., Li, L., Li, M., and Witasse, O.: Simulation Study for Precise Orbit Determination of a Callisto Orbiter and Geodetic Parameter Recovery, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13996, https://doi.org/10.5194/egusphere-egu23-13996, 2023.

When a high-voltage charged tether is put into streaming space plasma, the tether’s electric field disturbs the flow of plasma ions and thereby taps momentum from the plasma flow [1-4]. The effect is called electrostatic Coulomb drag. One application is the electric solar wind sail which uses the solar wind to generate interplanetary propulsion [1, 2]. Another application is the Plasma Brake [3, 4] which uses the ionospheric ram flow to generate Coulomb drag that slowly de-orbits the satellite. Both positive and negative tether polarities work. The plasma physics is different, but the net effect is a transfer of momentum in both cases. The reasons are somewhat complicated, but there is good motivation to select positive polarity in the solar wind case and negative polarity in the ionospheric Plasma Brake case. Measurement of Coulomb drag in Low Earth Orbit and testing deployment of tether is to be carried out by ESTCube-2 cubesat [5] which is scheduled for launch in spring 2023, and forthcoming Foresail cubesat scheduled for launch later in 2023-2024.

Project DragLiner is ongoing and funded by ESA to define requirements and a preliminary design of a passive Coulomb Drag based deorbit system capable of bringing down LEO spacecrafts in an order of magnitude shorter time than the current regulations of re-enter time for the spacecraft (25 years). Other main requirements for the deorbiting system are low mass and independence from the spacecraft resources. The project will also create a TRL 4 prototype of a Plasma Brake module that can be used to deorbit a few hundred kilogram satellite or launcher upper stage from Low Earth Orbit. The module deploys ~5 km long tether that is made of four 25-50 micrometre diameter conductive wires. In addition to aluminium wires used previously in Cubesat projects we will also evaluate more advanced carbon fibre composite wires. The redundant multi-wire tether structure is used so that the tether does not break even when micrometeoroids cut some of its wires. The tether is deployed from a storage reel. The tether is kept at -1 kV voltage by an onboard high-voltage source. A ~100 m long metal-coated tape tether is used as an electron-gathering surface that closes the current loop. Alternatively, conducting parts of the debris satellite could be used for electron gathering. The power consumption is a few watts. 

Project Dragliner uses basic Space Plasma Physics to solve a practical and important problem of keeping satellite orbits clean for future generations and preventing a catastrophic Kessler syndrome scenario.

[1] Janhunen, P., Electric sail for spacecraft propulsion, J. Prop. Power, 20, 763-764, 2004.

[2] Janhunen, P. and A. Sandroos, Simulation study of solar wind push on a charged wire: basis of solar wind electric sail propulsion, Ann. Geophys., 25, 755-767, 2007.

[3] Janhunen, P., Electrostatic plasma brake for deorbiting a satellite, J. Prop. Power, 26, 370-372, 2010.

[4] Janhunen, P., Simulation study of the plasma-brake effect, Ann. Geophys., 32, 1207-1216, 2014.

[5] Iakubivskyi, I., et al., Coulomb drag propulsion experiment of ESTCube-2 and FORESAIL-1, Acta Astronautica, 177, 771-783, 2020.

How to cite: Genzer, M., Janhunen, P., Haukka, H., Kestilä, A., Hieta, M., Peitso, P., Yli-Opas, P., Ploskonka, H., Toivanen, P., Sievinen, J., Marques, M., Macieira, D., El Moumen, A., Gholami, F., Olivares-Mendez, M., Yalcin, B. C., and Martinez Luna, C.: Project DragLiner: Harnessing plasma Coulomb drag for satellite deorbiting to keep orbits clean, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14692, https://doi.org/10.5194/egusphere-egu23-14692, 2023.

Orbital radars, such as the SHAllow RADar (SHARAD) [1] or the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) [2] instruments on board Mars Reconnaissance Orbiter (MRO) and Mars Express (MEX) respectively, provide valuable data about the Martian subsurface [3,4].

Common analysis methodologies comprise a direct comparison between the radargram (RDR) and the corresponding Surface Clutter Simulation (SCS) to visually spot any subsurface reflector. The surface time delays converted in the space domain are then compared with the corresponding topographic profile to check if any discrepancy occurred. and thus be mistaken for subsurface reflections. Once confirmed that the subsurface reflector is valid, the proper picking can be performed by looking at the radargram and both the radargram and the simulation power intensities. Finally, it is possible to estimate the real dielectric constant ε', which is the real component of the complex permittivity ε' - iε'' using Equation Eq1 [3]:

where Δt is the two-way travel time between the surface and the subsurface reflector, c is the speed of light in a vacuum and h is the reflector’s depth. Assuming different values for ε' and inverting Eq1, is possible to estimate the depth, thus the thickness of the reflector’s unit. In this work, we present the first pre-release of a user-friendly interface, with which is possible to easily perform the above analysis while granting robustness and reproducibility. Besides, it is possible to implement further custom processing functions to increase the accuracy of the results and/or expand the tool capabilities. We started the development using SHARAD US RDR and SCS, while MARSIS compatibility is under implementation. We provided also additional Jupyter notebooks for data download. This tool is based on the Jupyter lab environment and open-source python packages served as a docker container.

Open Research: The tool presented here is available on GitHub [5]

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreements No 101004214 and No 871149.

References:

[1] Seu, R., et al., SHARAD Sounding Radar on the Mars Reconnaissance Orbiter., doi:10.1029/2006JE002745.

[2] Jordan, R., et al., The Mars Express MARSIS Sounder Instrument. doi:10.1016/j.pss.2009.09.016.

[3] Shoemaker, E.S., et al., New Insights Into Subsurface Stratigraphy Northwest of Ascraeus Mons, Mars, Using the SHARAD and MARSIS Radar Sounders. doi:10.1029/2022JE007210.

[4] Lauro, S.E., et al., Using MARSIS Signal Attenuation to Assess the Presence of South Polar Layered Deposit Subglacial Brines. doi:10.1038/s41467-022-33389-4.

[5] Nodjoumi, G. MORDOR - Mars Orbital Radar Data Open-Reader 2023.

How to cite: Nodjoumi, G., Lauro, S. E., and Rossi, A. P.: A novel user-friendly Jupyter-based tool for analysing orbital subsurface sounding radar data., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14760, https://doi.org/10.5194/egusphere-egu23-14760, 2023.

Exploiting the Alfvénic structures of the solar wind is an established method for calibrating spaceborne magnetometers. However, not every statistical property of Alfvén waves follows a uniform distribution, so calibration accuracy in certain sensor directions may be significantly affected by the choice of the data set used. This work examines the statistical properties of Alfvénic disturbances and other structures of the solar wind in a wide range of spatial and temporal scales using data from the current BepiColombo mission, now in the inner solar system, the lunar and Earth-bound satellites of the THEMIS and ARTEMIS missions, and the Earth-bound MMS mission. The influence of the data selection on calibration is characterized and quantified. We benefit from the fact that the magnetometers of the above-mentioned missions have been partially calibrated by independent methods, using the spacecraft spin or alternative observations of the total magnetic field.

How to cite: Mieth, J. Z. D., Plaschke, F., Auster, U., Fischer, D., Heyner, D., and Magnes, W.: Statistics of Alfvénic structures in the Solar Wind and their impact on Magnetometer Calibration, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14810, https://doi.org/10.5194/egusphere-egu23-14810, 2023.

Callio SpaceLab is an initiative for international space testing, R&D for future human space exploration. SpaceLab's extremely confined environment of the mine and surroundings provide testbeds to simulate human space exploration, analogue astronaut training and experiences for space research and systems in extreme environments on Earth.

Many steps need to be taken here on Earth to put a (hu)man on the Moon and later on Mars. The Earth-based simulation environments are called Terrestrial analogue sites or space analogues. Some analogues are more general, but some have characteristics similar to the extra-terrestrial conditions: e.g., Venus has an analogue environment at Mt. Etna (1), Italy, Mars at Atacama desert (2), Chile and Moon (3), Mauna Kea, Hawai, USA.

Space analogues research covers many topics ranging from testing of habitats and other constructions, fieldwork, in-situ resource utilisation and vehicles; some concentrate on low gravity  (simulated, e.g., in pools) and confinement from the existing world in enclosed environments.

Callio SpaceLab is a concept being developed at the Pyhäsalmi mine, Finland. It is one of Europe’s deepest  (1.4 km) base metal mines. The underground mining ended in 8/2022, but that is just the beginning. The Pyhäjärven Callio is developing the site for a second life, including underground pumped-hydro energy storage, a solar park, FUTUREMINE testing environment for autonomous mining equipment, and more (4,5). Research activities are coordinated by the University of Oulu´s Kerttu Saalasti Institute.

In order to survive on the extraterrestrial landscapes Moon and Mars, one needs to bring enough protection to sustain life and activities. Mine is a suitable terrestrial analogue test environment for confinement studies, biology, astrobiology, in-situ resource utilisation, scientific drilling, rover testing (inclines up to1:7), communications systems testing, space design-, art- and culture projects, etc. (6). The mine has extensive connectivity. Deep space communications can be simulated for different missions, from spaceflights to extraterrestrial bases and activities both on surfaces and in the depth of space objects and celestial bodies.

The site´s hosting rock is a massive volcanogenic sulfide (VMS) deposit formed 1.9 Ga (7). Exploration drilling has found saline water pockets dated at least 30 Ma old. The water samples have shown traces of bacteria common to deep subsurface environments (8).

References

• Gabriel V.,  et al. Mineralogy and Spectroscopy of Mount Etna Lava Flows as an Analogue to Venus. https://ui.adsabs.harvard.edu/abs/2022LPICo2678.2255E
• Azua-Bustos A.,  et al. The Atacama Desert in Northern Chile as an Analog Model of Mars. 2022. https://doi.org/10.3389/fspas.2021.810426
• Inge IL ten K.,  et al. Mauna Kea, Hawaii, as an Analog Site for Future Planetary Resource Exploration: Results from the 2010 ILSO-ISRU Field-Testing Campaign. Journal of Aerospace Engineering. https://doi:10.1061/(ASCE)AS.1943-5525.0000200
• Callio - Mine for Business. 2023. https://callio.info
• Joutsenvaara J.,  et al. Callio Lab - the deep underground research centre in Finland, Europe. 2021.  https://doi.org/10.1088/1742-6596/2156/1/012166
• Tenetz A., More than Planet - Deep residency and workshop, creative Eu-project - 2022-2025. http://www.photonorth.fi/fi/projektit/more-than-planet/
• Imaña M,  et al., 3D modeling for VMS exploration in the Pyhäsalmi district, Central Finland in. In: Proceedings of the 12th Biennial SGA Meeting. 2013. p. 12–5.
• Miettinen H, et al., Microbiome composition and geochemical characteristics of deep subsurface high-pressure environment, Pyhasalmi mine Finland. https://doi.org/10.3389%2Ffmicb.2015.01203

How to cite: Joutsenvaara, J., Tenetz, A., Puputti, J., and Kotavaara, O.: Callio SpaceLab – Sustainable living, sustaining life, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15409, https://doi.org/10.5194/egusphere-egu23-15409, 2023.

Increasing coverage of commercial and public satellites allows us to monitor the pulse of the Earth in ever-shorter frequency (Zhu et al., 2017). Together with the rise of deep learning in artificial intelligence (AI) (LeCun et al., 2015), the field of AI for Earth Observation (AI4EO) is growing rapidly. However, many supervised deep learning techniques are data-hungry, which means that annotated data in large quantities are necessary to help these algorithms reach their full potential. In many Earth Observation applications such as change detection, this is often infeasible because high-quality annotations require manual labeling which is time-consuming and costly.  

Self-supervised learning (SSL) can help tackle the issue of limited label availability in AI4EO. In SSL, an algorithm is pretrained with tasks that only require the input data without annotation. Notably, Masked Autoencoders (MAE) have shown promising performances recently where a Vision Transformer learns to reconstruct a full image with only 25% of it as input. We hypothesize that the success of MAEs also extends to satellite imagery and evaluate this with a change detection downstream task. In addition, we provide a multitemporal DINO baseline which is another widely successful SSL method. Further, we test a second version of MAEs, which we call GeoMAE. GeoMAE incorporates the location and date of the satellite image as auxiliary information in self-supervised pretraining. The coordinates and date information are passed as additional tokens to the MAE model similar to the positional encoding. 
The pretraining dataset used is the RapidAI4EO corpus which contains multi-temporal Planet Fusion imagery for a variety of locations across Europe. The dataset for the downstream task also uses Planet Fusion in pairs as input data. These are provided on a 600m * 600m patch level three months apart together with a classification if the respective patch has changed in this period. Self-supervised pretraining is done for up to 150 epochs where we take the model with the best validation performance on the downstream task as a starting point for the test set. 

We find that the regular MAE model scores the best on the test set with an accuracy of 81.54% followed by DINO with 80.63% and GeoMAE with 80.02%. Pretraining MAE with ImageNet data instead of satellite images results in a notable performance loss down to 71.36%. Overall, our current pretraining experiments can not yet confirm our hypothesis that GeoMAE is advantageous compared to regular MAE. However, in similar spirit, Cong et al. (2022) recently introduced SatMAE which outlines that for other remote sensing applications, the combination of auxiliary information and novel masking strategies is a key factor. Therefore, it seems that a combination of location and time inputs together with adapted masking may also hold the most potential for change detection. There is ample potential for future research in geo-specific applications of MAEs and we provide a starting point for this with our experimental results for change detection. 

How to cite: Kondmann, L., Senaras, C., Asano, Y. M., Rana, A. S., Wania, A., and Zhu, X. X.: Geography-Aware Masked Autoencoders for Change Detection in Remote Sensing, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2843, https://doi.org/10.5194/egusphere-egu23-2843, 2023.

New models are emerging from Artificial Intelligence (AI) and its sub-fields, in particular, Machine Learning and Deep Learning that are being applied in different application areas including geography (e.g., land cover identification and traffic volume forecasting based on spatial data). Different from well-known datasets often used to develop AI models (e.g., ImageNet for image classification), spatial data has an intrinsic feature, i.e., spatial heterogeneity, which leads to varying relationships across different regions between the independent (i.e., the model input X) and dependent variables (i.e., the model output Y). This makes it difficult to conduct large-scale studies with a single robust AI model. In this study, we draw on the idea of modular learning, i.e., to decompose large-scale tasks into sub-tasks for specific sub-regions and use multiple AI models to achieve these sub-tasks. The decomposition is based on the spatial characteristics to ensure that the relationship between independent and dependent variables is similar in each sub-region. We explore this approach for forecasting COVID-19 cases in Germany using spatiotemporal data (e.g., weather data and human mobility data) as an example and compare the prediction tasks with a single model to the proposed decomposition learning procedure in terms of accuracy and efficiency. This study is part of the project DAKI-FWS which is funded by the Federal Ministry of Economic Affairs and Climate Action in Germany to develop an early warning system to stabilize the German economy.

How to cite: Cheng, X., Arndt, J., Marquez, E., and Ma, J.: Decomposition learning based on spatial heterogeneity: A case study of COVID-19 infection forecasting in Germany, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3267, https://doi.org/10.5194/egusphere-egu23-3267, 2023.

The iMagine project is devoted to developing and delivering imaging data and services for aquatic science. Started in September 2022, the project will provide a portfolio of image data collections, high-performance image analysis tools empowered with Artificial Intelligence, and best practice documents for scientific image analysis. These services and documentation will enable better and more efficient processing and analysis of imaging data in marine and freshwater research, accelerating our scientific insights about processes and measures relevant to healthy oceans, seas, and coastal and inland waters. By building on the European Open Science Cloud compute platform, iMagine delivers a generic framework for AI model development, training, and deployment, which researchers can adopt for refining their AI-based applications for water pollution mitigation, biodiversity and ecosystem studies, climate change analysis and beach monitoring, but also for developing and optimising other AI-based applications in this field. The iMagine AI development and testing framework offers neural networks, parallel post-processing of extensive data, and analysis of massive online data streams in distributed environments. The synergies among the eight aquatic use cases in the project will lead to common solutions in data management, quality control, performance, integration, provenance, and FAIRness and contribute to harmonisation across RIs. The resulting iMagine AI development and testing platform and the iMagine use case applications will provide another component to the European marine data management landscape, valid for the Digital Twin of the Ocean, EMODnet, Copernicus, and international initiatives. 

How to cite: Fava, I., Thijsse, P., Sipos, G., and Schaap, D.: Using AI and ML to support marine science research, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4929, https://doi.org/10.5194/egusphere-egu23-4929, 2023.

Eddies are circular rotating water masses, which are usually generated near the large ocean currents, e.g., Gulf Stream. Monitoring eddies and gaining knowledge on eddy statistics over a large region are important for fishery, marine biology studies, and testing ocean models.

At mesoscale, eddies are observed in radar altimetry, and methods have been developed to identify, track and classify them in gridded maps of sea surface height derived from multi-mission data sets. However, this procedure has drawbacks since much information is lost in the gridded maps. Inevitably, the spatial and temporal resolution of the original altimetry data degrades during the gridding process. On the other hand, the task of identifying eddies has been a post-analysis process on the gridded dataset, which is, by far, not meaningful for near-real time applications or forecasts. In the EDDY project at the University of Bonn, we aim to develop methods for identifying eddies directly from along track altimetry data via a machine (deep) learning approach.

Since eddy signatures (eddy boundary and highs and lows on sea level anomaly, SLA) are not possible to extract directly from along track altimetry data, the gridded altimetry maps from AVISO are used to detect eddies. These will serve as the reference data for Machine Learning. The eddy detection on 2D grid maps is produced by open-source geometry-based approach (e.g., py-eddy-tracker, Mason et al., 2014) with additional constraints like Okubo-Weiss parameter. Later, Sea Surface Temperature (SST) maps of the same region and date (also available from AVISO) are used for manually cleaning the reference data. Noting that altimetry grid maps and SST maps have different temporal and spatial resolution, we also use the high resolution (~6 km) ocean modeling simulation dataset (e.g., FESOM, Finite Element Sea ice Ocean Model). In this case, the FESOM dataset provides a coherent, high-resolution SLA and SST, salinity maps for the study area and is a potential test basis to develop the deep learning network.

The single modal training via a Conventional Neural Network (CNN) for the 2D altimetry grid maps produced excellent dice score of 86%, meaning the network almost detects all eddies in the Gulf Stream, which are consistent with reference data. For the multi-modal training, two different training networks are developed for 1D along-track altimetry data and 2D grid maps from SLA and SST, respectively, and then they are combined to give the final classification output. A transformer model is deemed to be efficient for encoding the spatiotemporal information from 1D along track altimetry data, while CNN is sufficient for 2D grid maps from multi-sensors.

In this presentation, we show the eddy classification results from the multi-modal deep learning approach based on along track and gridded multi-source datasets for the Gulf stream area for the period between 2017 and 2019. Results show that multi-modal deep learning improve the classification by more than 20% compared to transformer model training on along-track data alone.

How to cite: Abulaitijiang, A., Bolmer, E., Roscher, R., Kusche, J., and Fenoglio-Marc, L.: Eddy identification from along-track altimeter data with multi-modal deep learning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6818, https://doi.org/10.5194/egusphere-egu23-6818, 2023.

Machine learning models are able to capture highly complex, nonlinear relationships, and have been used in recent years to accurately predict crop yields at regional and national scales. This success suggests that the use of ‘interpretable’ or ‘explainable’ machine learning (XAI) methods may facilitate improved scientific understanding of the compounding interactions between climate, crop physiology and yields. However, studies have identified implausible, contradicting or ambiguous results from the use of these methods. At the same time, researchers in fields such as ecology and remote sensing have called attention to issues with robust model evaluation on spatiotemporal datasets. This suggests that XAI methods may produce misleading results when applied to spatiotemporal datasets, but the impact of model evaluation strategy on the results of such methods has not yet been examined.

In this study, machine learning models are trained to predict simulated crop yield, and the impact of model evaluation strategy on the interpretation and performance of the resulting models is assessed. Using data from a process-based crop model allows us to then comment on the plausibility of the explanations provided by common XAI methods. Our results show that the choice of evaluation strategy has an impact on (i) the interpretations of the model using common XAI methods such as permutation feature importance and (ii) the resulting model skill on unseen years and regions. We find that use of a novel cross-validation strategy based on clustering in feature-space results in the most plausible interpretations. Additionally, we find that the use of this strategy during hyperparameter tuning and feature selection results in improved model performance on unseen years and regions. Our results provide a first step towards the establishment of best practices for model evaluation strategy in similar future studies.

How to cite: Sweet, L., Müller, C., Anand, M., and Zscheischler, J.: Model evaluation strategy impacts the interpretation and performance of machine learning models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8479, https://doi.org/10.5194/egusphere-egu23-8479, 2023.

Predictive learning from data usually is formulated as a problem of finding the best connection between input and output spaces by optimizing well-defined cost or risk functions.

In geo-environmental studies input space is usually constructed from the geographical coordinates and features generated from different sources of available information (feature engineering), by applying expert knowledge, using deep learning technologies and taking into account the objectives of the study. Often, it is not known in advance if the input space is complete or contains redundant features. Therefore, unsupervised learning (UL) is essential in environmental data analysis, modelling, prediction and visualization. UL also helps better understand the data and phenomena they describe as well as in interpreting/communicating modelling strategies and the results in the decision-making process.

The main objective of the present investigation is to review some important topics in unsupervised learning from environmental data: 1) quantitative description of the input space (“monitoring network”) structure using global and local topological and fractal measures, 2) dimensionality reduction, 3) unsupervised feature selection and clustering by applying a variety of machine learning algorithms (kernel-based, ensemble learning, self-organizing maps) and visualization tools.

Major attention is paid to the simulated and real spatial data (pollution, permafrost, geomorphological and wind fields data).  Considered case studies have different input space dimensionality/topology and number of measurements. It is confirmed that UL should be considered an integral part of a generic methodology of environmental data analysis. Comprehensive comparisons and discussions of the results conclude the research.

How to cite: Kanevski, M.: On Unsupervised Learning from Environmental Data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9437, https://doi.org/10.5194/egusphere-egu23-9437, 2023.

Unsupervised classification techniques are becoming essential to extract information from the wealth of data that Earth observation satellites and other sensors currently provide. These datasets are inherently complex to analyze due to the extent across multiple dimensions - spatial, temporal, and often spectral or band dimension – their size, and the high resolution of current sensors. Traditional one-dimensional cluster analysis approaches, which are designed to find groups of similar elements in datasets such as rasters or time series, may come short of identifying patterns in these higher-dimensional datasets, often referred to as data cubes. In this context, we present our Clustering Geodata Cubes (CGC) software, an open-source Python package that implements a set of co- and tri-clustering algorithms to simultaneously group elements across two and three dimensions, respectively. The package includes different implementations to most efficiently tackle datasets that fit into the memory of a single machine as well as very large datasets that require cluster computing. A refining strategy to facilitate data pattern identification is also provided. We apply CGC to investigate gridded datasets representing the predicted day of the year when spring onset events (first leaf, first bloom) occur according to a well-established phenological model. Specifically, we consider spring indices computed at high spatial resolution (1 km) and continental scale (conterminous United States) for the last 40+ years and extract the main spatiotemporal patterns present in the data via CGC co-clustering functionality.  

How to cite: Nattino, F., Ku, O., Grootes, M. W., Izquierdo-Verdiguier, E., Girgin, S., and Zurita-Milla, R.: Clustering Geodata Cubes (CGC) and Its Application to Phenological Datasets, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11601, https://doi.org/10.5194/egusphere-egu23-11601, 2023.

Industrial pollution remains a major challenge in spite of recent technological developments and purification procedures. To effectively monitor atmosphere contamination, data from air quality networks should be coupled with advanced spatiotemporal statistical methods.

Our previous studies showed that standard interpolation techniques (like inverse distance weighting, linear or spline interpolation, kernel-based Gaussian Process Regression, GPR) are quite limited for the simulation of a smoke-like narrow-directed industrial pollution in the vicinity of the source (a few tenths of kilometers). In this work, we try to apply GPR, based on statistically estimated covariances. These covariances are calculated using СALPUFF atmospheric pollution dispersion model for a one-year simulation in the Kryvyi Rih region. The application of GPR permits taking into account high correlations between pollution values in neighboring points revealed by modeling. The result of the GPR covariance-based technique is compared with other interpolation techniques. It can be used then in the estimation and optimization of air quality networks.

How to cite: Sokolov, A., Delbarre, H., Boldyriev, D., Bulana, T., Molodets, B., and Grabovets, D.: Industrial Atmospheric Pollution Estimation Using Gaussian Process Regression, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12773, https://doi.org/10.5194/egusphere-egu23-12773, 2023.

Land ecosystems dampen the increase of atmospheric CO₂ by storing carbon in soils and vegetation. In order to estimate how long carbon stays in land ecosystems, a detailed knowledge about the distribution of carbon in different vegetation components is needed. Current Earth observation products provide estimates about total above-ground biomass but do not further separate between carbon stored in trees, understory vegetation, shrubs, grass, litter or woody debris. Here we present an approach in which we link several Earth observation products with a ground-based database to estimate biomass in various vegetation components. Therefore, we use information about the statistical distribution of biomass components provided by the North American Wildland Fuels Database (NAWFD), which are however not available as geocoded data. We use ESA CCI AGB version 3 data from 2010 as a proxy in order to link the NAWFD data to the spatial information from Earth observation products. The biomass and corresponding uncertainty from the ESA CCI AGB and a map of vegetation types are used to select the likely distribution of vegetation biomass components from the set of in-situ measurements of tree biomass. We then apply Isolation Forest outlier detection and bootstrapping for a robust comparison of both datasets and for uncertainty estimation. We use Random Forest and Gaussian Process regression to predict the biomass of trees, shrubs, snags, herbaceous vegetation, coarse and fine woody debris, duff and litter from ESA CCI AGB and land cover, GEDI canopy height, Sentinel-3 LAI and bioclimatic data. The regression models reach high predictive power and allow to also extrapolate to other regions. Our derived estimates of vegetation carbon stock components provide a more detailed view on the land carbon storage and contribute to an improved estimate of potential carbon emissions from respiration, disturbances and fires.

How to cite: Kinalczyk, D., Wessollek, C., and Forkel, M.: Estimating vegetation carbon stock components by linking ground databases with Earth observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12933, https://doi.org/10.5194/egusphere-egu23-12933, 2023.

High resolution in weather and climate was always a common and ongoing goal of the community. In this regards, machine learning techniques accompanied numerical and statistical methods in recent years. Here we demonstrate that artificial intelligence can skilfully downscale low resolution climate model data when combined with numerical climate model data. We show that recently developed image inpainting technique perform accurate super-resolution via transfer learning using the HighResMIP of CMIP6 (Coupled Model Intercomparison Project Phase 6) experiments. Its huge data base offers a unique training opportunity for machine learning approaches. The transfer learning purpose allows also to downscale other CMIP6 experiments and models, as well as observational data like HadCRUT5. Combined with the technology of Kadow et al. 2020 of infilling missing climate data, we gain a neural network which reconstructs and downscales the important observational data set (IPCC AR6) at the same time. We further investigate the application of our method to downscale quantities predicted from a numerical ocean model (ICON-O) to improve computation times. In this process we focus on the ability of the model to predict eddies from low-resolution data.

An extension to:

Kadow, C., Hall, D.M. & Ulbrich, U. Artificial intelligence reconstructs missing climate information. Nature Geoscience 13, 408–413 (2020). https://doi.org/10.1038/s41561-020-0582-5

How to cite: Witte, M., Filippou, D., Plésiat, É., Meuer, J., Thiemann, H., Hall, D., Ludwig, T., and Kadow, C.: From Super-Resolution to Downscaling - An Image-Inpainting Deep Neural Network for High Resolution Weather and Climate Models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13196, https://doi.org/10.5194/egusphere-egu23-13196, 2023.

To assess the impact of anthropogenic and natural causes on land use and land use cover change, mapping of spatial and temporal changes is increasingly applied. Due to the availability of satellite image archives, remote sensing (RS) data-based machine learning models are in particular suitable for mapping and analysing land use and land cover changes. Most often, models trained with current RS data are employed to estimate past land cover and land use using available RS data with the assumption that the trained model predicts past data values similar to the accuracy of present data. However, machine learning models trained on RS data from particular locations and times may not be well transferred to new locations and time datasets due to various reasons. This study aims to assess the spatial-temporal transferability of the RS data models in the context of agricultural land use mapping. The study was designed to map agricultural land use (5 classes: maize, grasslands, summer crops, winter crops, and mixed crops) in two regions in Germany (North Hesse and Weser Ems) between the years 2010 and 2018 using Landsat archive data (i.e., Landsat 5, 7, and 8). Three model transferability scenarios were evaluated, a) temporal - S1, b) spatial - S2 and c) spatial-temporal - S3. Two machine learning models (random forest - RF and Convolution Neural Network - CNN) were trained. For each transferability scenario, class-level F1 and macro F1 values were compared between the reference and targeted transferability systems. Moreover, to explain the results of transferability scenarios, transferability results were further explored using dissimilarity index and area of applicability (AOA) concepts. The average macro F1 value of the trained model for the reference scenario (no transferability) was 0.75. For assessed transferability scenarios, the average macro F1 values were 0.70, 0.65 and 0.60, for S1, S2, and S3 respectively. It shows that, when predicting data from different spatial-temporal contexts, the model performance is decreasing. In contrast, the average proportion of the data inside the AOA did not show a clear pattern for different scenarios. In the context of RS data-related model building, spatial-temporal transferability is essential because of the limited availability of the labelled data. Thus, the results from this case study provide an understanding of how model performance changes when the model is transferred to new settings with data from different temporal and spatial domains.

How to cite: Wijesingha, J., Dzene, I., and Wachendorf, M.: Spatial-temporal transferability assessment of remote sensing data models for mapping agricultural land use, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14716, https://doi.org/10.5194/egusphere-egu23-14716, 2023.

Machine learning algorithms have become popular tools for the analysis of spatial data. However, a number of studies have demonstrated that the application of machine learning algorithms in a spatial context has limitations. New geographic locations may lie outside of the data range for which the model was trained, and estimates of model performance may be too optimistic, when spatial autocorrelation of geographic data is not properly accounted for in cross-validation. We here use artificially created spatial data fields to conduct a series of experiments to further investigate the potential pitfalls of random forest regression applied to spatial data. We provide new insights on previously reported limitations and identify further limitations. We demonstrate that the same mechanism that leads to overoptimistic estimates of model performance (when based on ordinary random k-fold cross-validation) can also lead to a deterioration of model performance. When covariates contain sufficient information to deduce spatial coordinates, the model can reproduce any spatial pattern in the training data even if it is entirely or partly unrelated to the covariates. The presence of spatially correlated residuals in the training data changes how the model utilizes the information of the covariates and impedes the identification of the actual relationship between covariates and response. This reduces model performance when the model is applied to data with a different spatial structure. Under such conditions, machine learning methods that are sufficiently flexible to fit to autocorrelated residuals (such as random forest) may not be an optimal choice. Better models may be obtained using less flexible but more transparent approaches such as generalized linear models or additive models.

How to cite: Heinke, J., Müller, C., and Gerten, D.: Limitations of machine learning in a spatial context, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16096, https://doi.org/10.5194/egusphere-egu23-16096, 2023.

Levee systems are designed to reduce the risk of water-related natural hazards (e.g., flooding) in areas behind levees. Most levees in the U.S. are designed to protect people and facilities against the impacts of the 100-year floods. However, the current climate change is increasing the probability of the occurrence of 500-year flood events that in turn increases the likelihood of economic loss, environmental damage, and fatality that disproportionately impacts communities of color and low-income groups facing socio-economic inequities in leveed areas. The increased frequency and intensity of flooding is putting extra pressure on emergency responders that often require diverse, multi-dimensional data originating from different sources to make sound decisions. Currently, the integration of these heterogeneous data acquired by diverse sensors and emergency agencies about environmental, hydrological, and demographic indicators requires costly and complex programming and analysis that hinder rapid disaster management efforts. Our domain ‘Levee System Ontology (LSO)’ resolves the data integration and software interoperability issues by semantically modeling the static aspects, dynamic processes, and information content of the levee systems by extending the well-structured, top-level Basic Formal Ontology (BFO) and mid-level Common Core Ontologies (CCO). LSO’s class and property names follow the terminology of the National Levee Database (NLD), allowing data scientists using NLD data to constrain their classifications based on the knowledge represented in LSO. In addition to modeling the information related to the characteristics and status of the structural components of the levee system, LSO represents the residual risk in leveed areas, economic and environmental losses, and damage to facilities in case of breaching and/or overtopping of levees. LSO enables reasoning to infer components and places along levees and floodwalls where the system requires inspection, maintenance, and repair based on the status of system components. The ontology also represents the impact of flood management activities on different groups of people from an environmental justice perspective, based on the principles of DEI (diversity, equity, inclusion) as defined by the U.N. Sustainable Development Goals.

How to cite: Davarpanah, A., Nguy Robertson, A. L., Lipscomb, M., McCord, J. w., and Morris, A.: Knowledge Representation of Levee Systems - an Environmental Justice Perspective, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16768, https://doi.org/10.5194/egusphere-egu23-16768, 2023.

Halogenated organic and inorganic compounds, in particular those containing chlorine, bromine and iodine are known to contribute to the global ozone depletion as well as directly and indirectly to climate forcing. As a result of the Montreal Protocol (1987), the chlorine and bromine loadings of the stratosphere are closely monitored, while the role of iodinated compounds to the stratospheric ozone photochemistry is still uncertain.

To address the questions concerning bromine and iodine compounds, a compact solar occultation instrument (TotalBrO) has been specifically designed to measure BrO, IO (iodine oxide) and other UV/Vis absorbing gases by means of Differential Optical Absorption Spectroscopy (DOAS) from aboard a stratospheric balloon. The instrument (power consumption < 100 W) comprises of an active camera-based solar tracker (LxWxH ~ 0.40 m x 0.40 m x 0.50 m, weight ~ 12 kg) and a spectrometer unit (LxWxH ~ 0.45 m x 0.40 m x 0.40 m, weight ~ 25 kg). The spectrometer unit houses two grating spectrometers which operate in vacuum and under temperature stabilization by an ice-water bath.

We discuss the performance of the TotalBrO instrument during the first two deployments on stratospheric balloons launched from Kiruna in August, 2021 and from Timmins in August, 2022 within the HEMERA program. Once the balloon gondola was azimuthally stabilized the solar tracker was able to follow the sun with a 1σ precision lower than 0.02° up to solar zenith angles (SZAs) of 95°. The spectral retrieval (of 46 spectra acquired at SZA between 84° and 90°) allowed us to infer the BrO mixing ratio above 32 km altitude. The total bromine in the middle stratosphere is inferred by accounting for the BrO/Br_y partitioning derived from a photochemical model.

How to cite: Voss, K., Holzbeck, P., Kleinschek, R., Höpfner, M., Wetzel, G., Sinnhuber, B.-M., Pfeilsticker, K., and Butz, A.: Total stratospheric bromine inferred from balloon-borne solar occultation bromine oxide (BrO) measurements using the new TotalBrO instrument, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1981, https://doi.org/10.5194/egusphere-egu23-1981, 2023.

Oil sands are a prominent unconventional source of petroleum. Total organic carbon measurements via an aircraft campaign (Spring-Summer 2018) revealed emissions above Canadian oil sands exceeding reported values by 1900-6300%. The “missing” compounds were predominantly intermediate- and semi-volatile organic compounds, which are prolific precursors to secondary organic aerosol formation. 

Here we use a novel combination of aircraft-based measurements (including total carbon emissions measurements) and offline analytical instrumentation to characterize the mixtures of organic carbon and their volatility distributions above oil sands facilities. These airborne, real-time observations are supplemented by laboratory experiments identifying substantial, unintended emissions from waste management practices, emphasizing the importance of accurate facility-wide emissions monitoring and total carbon measurements to detect potentially vast missing emissions across sources.

Detailed chemical speciation confirms these observations near both surface mining and in-situ facilities were oil sands-derived, with facility-wide emissions around 1% of extracted petroleum—a comparable loss rate to natural gas extraction. Total emissions, spanning extraction through waste processing, were equivalent to total Canadian anthropogenic emissions from all sources. These results demonstrate that the full air quality and environmental impacts of oil sands operations cannot be captured without complete coverage of a wider volatility range of emissions.

How to cite: He, M., Ditto, J., Gardner, L., Machesky, J., Hass-Mitchell, T., Chen, C., Khare, P., Sahin, B., Fortner, J., Hayden, K., Wentzell, J., Mittermeier, R., Leithead, A., Lee, P., Darlington, A., Zhang, J., Moussa, S., Li, S.-M., Liggio, J., and Gentner, D.: Total organic carbon measurements reveal large discrepancies in reported petrochemical emissions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2923, https://doi.org/10.5194/egusphere-egu23-2923, 2023.

The UK’s large atmospheric research aircraft is a converted BAe 146 operated by the Facility for Airborne Atmospheric Measurements (FAAM). With a range of 2000 nautical miles, the FAAM aircraft is capable of operating all over the world and it has taken part in science campaigns in over 30 different countries since 2004. The aircraft can fly as low as 50 feet over the sea and sustain flight at 100 feet high. The service ceiling is nearly 11 km high. Typically, flights will last anywhere between one and six hours, and we will carry up to 18 scientists onboard, who guide the mission and support the operation of up to 4 tonnes of scientific equipment. Currently, the aircraft is undergoing a £49 million mid-life upgrade (MLU) program, which will extend its lifetime to at least 2040. The three overarching objectives of the MLU are to:

Safeguard the UK’s research capability – allowing the facility to meet the needs of the research community, enhance the range of services available, and respond to environmental emergencies.

Provide frontier science capability – meeting new and existing research needs and supporting ground-breaking science discoveries, with a flexible and world-class airborne laboratory.

Reduce environmental impact – maintaining and improving the performance of the facility, and minimising emissions and resource use from aircraft operation.

Presented here will be a brief history of the aircraft operations, including example science outcomes from all flights all over the world. In addition, detail of the ongoing upgrades, in particular the new and cutting-edge measurement capability for gases, aerosols, clouds, radiation and meteorology. Also presented will be the expected reductions in environmental impact of the aircraft and how these will be monitored.

How to cite: Lee, J.: The FAAM large atmospheric research aircraft: a brief history and future upgrades, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3473, https://doi.org/10.5194/egusphere-egu23-3473, 2023.

Despite the reduced nitrogen (N) cycle being central to global biogeochemistry, there are large uncertainties surrounding its sources and rate of cycling. Here, we present the first observations of gas-phase urea (CO(NH₂)₂) in the atmosphere from airborne high-resolution mass spectrometer measurements over the North Atlantic Ocean. We show that urea is ubiquitous in the marine lower troposphere during the Summer, Autumn and Winter flights but was found to be below the limit of detection during the Spring flights. The observations suggest the ocean is the primary emission source but further studies are required to understand the processes responsible for the air-sea exchange of urea. Urea is also frequently observed aloft due to long-range transport of biomass-burning plumes. These observations alongside global model simulations point to urea being an important, and as yet unaccounted for, component of reduced-N to the remote marine environment.  Since we show it readily partitions between gas and particle phases, airborne transfer of urea between nutrient rich and poor parts of the ocean can occur readily and could impact ecosystems and oceanic uptake of CO₂, with potentially important atmospheric implications.  

How to cite: Matthews, E., Bannan, T., Khan, M. A., Shallcross, D., Stark, H., Browne, E., Archibald, A., Bauguitte, S., Reed, C., Thamban, N., Wu, H., Lee, J., Carpenter, L., Yang, M., Bell, T., Allen, G., Percival, C., McFiggans, G., Gallagher, M., and Coe, H.: Airborne observations over the North Atlantic Ocean reveal the first gas-phase measurements of urea in the atmosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6620, https://doi.org/10.5194/egusphere-egu23-6620, 2023.

Monitoring climate change and stratospheric ozone budget requires accurate knowledge of the abundances of greenhouse gases and ozone depleting substances from the lower troposphere to the stratosphere. An infrared laser absorption spectrometer called SPECIES (acronym for SPECtromètre Infrarouge à lasErs in Situ) has been developed for balloon-borne trace gases measurements.

The complete instrument has been validated on the occasion of a flight in August 2021 in the polar region (Kiruna, Sweden) within the frame of the “KLIMAT 2021” campaign managed by CNES for the “MAGIC” project using concomitant balloon and aircraft flights. Results of this flight concerning CH4 and CO2 will be presented.

How to cite: Catoire, V., Xue, C., Krysztofiak, G., Jacquet, P., Chartier, M., and Robert, C.: In-situ trace-gas measurements from the ground to the stratosphere by an OF-CEAS balloon-borne instrument, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7804, https://doi.org/10.5194/egusphere-egu23-7804, 2023.

Since 1^st January 2020 the legal sulphur content of shipping fuel was decreased – from 3.5% to 0.5% by mass outside of the Sulphur Emission Control Areas (SECAs) to improve coastal air quality. A possible downside of this change was acceleration of climate change since sulphur is believed to be a negative climate forcer and sipping is one of its main sources. Further question was the level of compliance to the new rules, especially in the open waters. Another climate related aspect of shipping is recent growth in the liquified natural gas (LNG) tanker fleets. LNG is considered the greenest of the fossil fuels, however there are few empirical studies of methane emissions from marine LNG transport.

The Atmospheric Composition and Radiative forcing changes due to UN International Ship Emissions regulations (ACRUISE) project aims to address the above considerations. During three field campaigns the FAAM Airborne Laboratories’ large research aircraft was deployed to target ships in coastal shipping lanes and open waters. First measurements were performed in July 2019 (before regulation change) in shipping lanes along the Portuguese coast, the English Channel SECA and the Celtic Sea. Further two campaigns were delayed by the COVID-19 pandemic until September 2021 and April 2022, targeting ships in the Bay of Biscay, the English Channel SECA and the Celtic Sea. Throughout the project, nearly 300 ships were measured during 30 research flights, varying from plume aging and cloud interaction studies, through collecting bulk statistics in busy shipping lanes to comparing emissions in and out of SECA. This work focuses on the gaseous species measurements (SO₂, CO₂, CH₄ and VOCs from whole air samples). They are used to study changes in apparent sulphur fuel content of the ships observed throughout ACRUISE, plume composition and methane emissions from LNG tankers.

How to cite: Pasternak, D., Lee, J., Nelson, B., Alexiadou, M., Temple, L., Bauguitte, S., Batten, S., Hopkins, J., Andrews, S., Mathews, E., Bannan, T., Wu, H., Thamban, N., Marsden, N., Yang, M.-X., Bell, T., Coe, H., and Bower, K.: Ship emissions and apparent sulphur fuel content measured of board of a large research aircraft in international waters and Sulphur Emission Control Area, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7986, https://doi.org/10.5194/egusphere-egu23-7986, 2023.

Svalbard Integrated Arctic Earth Observing System (SIOS) is an international collaboration of 28 scientific institutions from 10 countries to build a collaborative research infrastructure that will enable better estimates of future environmental and climate changes in the Arctic. SIOS' mission is to develop an efficient observing system in Svalbard, share technology and data using FAIR principles, fill knowledge gaps in Earth system science and reduce the environmental footprint of science in the Arctic. This study presents SIOS' efforts to strengthen science, international collaboration and capacity building in the high Arctic archipelago of Svalbard through its airborne research infrastructure. SIOS supports the coordinated usage of its airborne remote sensing resources such as the Dornier aircraft and uncrewed aerial vehicles (UAVs) for improved research activities in Svalbard, complementing in situ and space-borne measurements and reducing the environmental footprint of research in Svalbard. Since 2019, SIOS in collaboration with its member institution Norwegian Research Centre (NORCE) installed, tested, and operationalised optical imaging sensors in the Lufttransport Dornier (DO228) passenger aircraft stationed in Longyearbyen under the SIOS-InfraNor project making it compatible with research use in Svalbard. Two optical sensors are installed onboard the Dornier aircraft; (1) the PhaseOne IXU-150 RGB camera and (2) the HySpex VNIR-1800 hyperspectral sensor. The aircraft with these cameras is configured to acquire aerial RGB imagery and hyperspectral remote sensing data in addition to its regular logistics and transport operation in Svalbard. Since 2020, SIOS has supported and coordinated around 50 flight hours to acquire airborne data using the Dornier aircraft and UAVs in Svalbard supporting around 20 scientific projects. The use of airborne imaging sensors in these projects enabled a variety of applications within glaciology, biology, hydrology, and other fields of Earth system science: Mapping glacier crevasses, generating DEMs for glaciological applications, mapping and characterising earth (e.g., minerals, vegetation), ice (e.g., sea ice, icebergs, glaciers and snow cover) and ocean surface features (e.g., colour, chlorophyll). The use of passenger aircraft warrants the following benefits: (1) regular logistics and research activities are optimally coordinated to reduce flight hours in carrying scientific observations, (2) project proposals for the usage of aircraft-based measurements facilitate international collaboration, (3) measurements conducted during 2020-21 are useful in filling the gaps in field based observations occurred due to the Covid-19 pandemic, (4) airborne data are used to train polar scientists as a part of the annual SIOS training course and upcoming data usability contest, (5) data is also useful for Arctic field safety as it can be used to make products such as high-resolution maps of crevassed areas on glaciers. In short, SIOS airborne remote sensing activities represent optimized use of infrastructure, promote capacity building, Arctic safety and facilitate international cooperation.

How to cite: Jawak, S., Sivertsen, A., Harcourt, W. D., Denkmann, R., Matero, I., Godøy, Ø., and Lihavainen, H.: Airborne remote sensing research infrastructure for strengthening science, international collaboration and capacity building in the Arctic, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8329, https://doi.org/10.5194/egusphere-egu23-8329, 2023.

 From December 2021 to May 2022, MeteoSwiss conducted a proof of concept with Meteomatics to demonstrate the capability of drones to provide data of sufficient quality and reliability on a routine operational basis. Meteodrones MM-670 were operated automatically 8 times per night at Payerne, Switzerland. 864 meteorological profiles were measured and compared to co-localized measurements including radiosoundings and remote-sensing instruments. To our knowledge, it is the first time that Meteodrone measurements are evaluated in such an intensive campaign.

The availability of the Meteodrone measurements over the whole campaign was 75.7% with 82.2% of the flights reaching the nominal altitude of 2000m above sea level. Using the radiosondes as a reference, the quality of the Meteodrone measurements can be quantified according to WMO requirements (WMO OSCAR , 2022). Applying this method, the temperature measured by the Meteodrone can be considered as a “breakthrough”, meaning that they are a significant improvement if they are used for high resolution Numerical Weather Prediction. The Meteodrone’s humidity and wind profiles are classified as “useful” for high-resolution numerical weather predictions, suggesting they can be used for assimilation in numerical models. The quality is similar compared to the temperature measured by a microwave radiometer and the humidity measured by a Raman Lidar. However, the wind measured by a Doppler Lidar was more accurate than the estimation of the Meteodrone.

This campaign opens the door for operational usage of automatic drones for meteorological applications.

How to cite: Hervo, M., Pasquier, J., Hammerschmidt, L., Weusthoff, T., Fengler, M., and Haefele, A.: First evaluation of a 6-months Meteodrone campaign, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11813, https://doi.org/10.5194/egusphere-egu23-11813, 2023.

Measurements involving water in the vapor phase have to deal with the stickiness of the H₂O molecule: The associated adsorption and desorption processes can increase the response time of these measurements significantly. To achieve short response times in scientific instrument design, hydrophobic surface materials are used to reduce surface interactions in the tubing that guides the sample towards the analyzer. The study presented here focuses on the effects of the tubing material choice, length, humidity level, gas flow rate, and temperature on the observed response time. We use an Optical Feedback Cavity Enhanced Absorption Spectrometer (OFCEAS) designed for stable water isotope measurements at low water concentration (< 1000 ppm), which we connect to two bottles containing humidified synthetic air of different water concentration using 6.6-m tubing of different materials and surface treatments. Other parameters that are varied are the flow rate and the temperature of the tubing. With proper selection of tubing material and surface treatment, the contribution from the tubing to the overall response time for low water concentration isotopic measurements can be sufficiently suppressed for it to be neglected.

How to cite: Miltner, M., Stoltmann, T., and Kerstel, E.: How inlet tubing material affects the response time of water vapor concentration measurements, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13766, https://doi.org/10.5194/egusphere-egu23-13766, 2023.

Land Surface Temperature (LST) is a key parameter to the understanding and modelling of many Earth system processes. Viewing and illumination geometry are known to have significant impacts on remotely sensed retrieval of LST, particularly for heterogeneous regions with mixed components. However, it is difficult to accurately quantify these impacts, in part due to the challenges of retrieving high-quality data for the different components in a scene at a variety of different viewing and illumination geometries over a time period where the real surface temperature and sun-sensor geometries are invariant. Previous field studies have attempted this through observations with aircraft-mounted single-band thermal cameras to further understanding of real-world conditions, but these sensors have limited accuracies and cannot be used to consider the angular variability of emissivity or to simulate multi-band satellite observations.

To redress this, the National Centre for Earth Observation’s Airborne Earth Observatory (NAEO) have developed and manufactured a modified mount for their state-of-the-art commercial pushbroom longwave hyperspectral airborne sensor, the Specim AisaOWL (102 narrowband channels across the 7.6 – 12.6 µm region). When mounted in standard mode, the field-of-view of the OWL sensor is 24° (± 12°), however the modified mount enables off-nadir measurements up to 48°. This has the potential to evaluate both thermal radiation and spectral emissivity directionality up to and beyond the view angles of most thermal satellite sensors. With LST now classified as an Essential Climate Variable, this work is particularly relevant as it will help to improve the accuracy of retrievals from current and future satellites (e.g. LSTM, SBG, TRISHNA).

In this presentation, we first present an overview of the design modifications that enable these high-angle observations and preliminary results from test flights before detailing how this setup will be used in an upcoming joint ESA-NASA campaign dedicated to quantifying and simulating thermal radiation directionality over agricultural regions at the satellite scale.

How to cite: Langsdale, M., Middleton, C., Wooster, M., Grosvenor, M., and Schuettemeyer, D.: Multi-angular airborne thermal observations: A new hyperspectral setup for simulating thermal radiation and emissivity directionality at the satellite scale, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14164, https://doi.org/10.5194/egusphere-egu23-14164, 2023.

Ammonia (NH₃) is mainly emitted in the atmosphere by anthropogenic activities, especially by agriculture. Excess emissions greatly disturb ecosystems, biodiversity, and air quality. Despite our awareness of these deleterious consequences, NH₃ concentrations are increasing in most industrialized countries. This underlines the need for more stringent regulations and good knowledge of the species gained through effective monitoring.

Since a decade, NH₃ is monitored from space, daily and globally, with thermal infrared sounders. However, their coarse spatial resolution (above 10 km) renders accurate quantification of NH₃ sources particularly challenging. Indeed, only the largest and most isolated NH₃ point sources have been identified and quantified from current observations and often only by exploiting long-term averages. To address the urgent need for better constraining NH₃ emissions, a new satellite, called Nitrosat, has been proposed in response to the 11^th ESA’s Earth Explorer call. The mission aims at mapping simultaneously NO₂ and NH₃ at a spatial resolution of 500 m at a global scale. With the support of ESA, almost 30 aircraft demonstration flights took place in Europe between 2020 and 2022. These flights mapped gapless areas of at least 10 by 20 km containing various sources of NO₂ and NH₃ using two instruments: the SWING instrument targeting NO₂ in the UV-VIS and Hyper-Cam LW measuring infrared spectra to observe NH₃.

Here we present NH₃ observations from campaigns performed in Italy in spring 2022. The Po Valley was the main target, as it is the largest (agricultural) hotspot of NH₃ in Europe.  Despite the presence of large background concentrations in the Po Valley, we show that the infrared measurements are able to expose a multitude of local agricultural hotspots such as cattle farms. A particularly successful campaign covering the region from Vetto to Colorno demonstrates measurement sensitivity to the gradual increase of NH₃ background concentrations outside and inside the Po Valley. We also discuss flights carried out further south in Italy targeting other emissions of NH₃, such as those from a soda ash plant, and the emissions from a fertilizer release experiment that was organized in collaboration with a farmer. We present the measurements both at their native horizontal resolution of 4 m and downsampled at the 500 m resolution of Nitrosat.

How to cite: Noppen, L., Clarisse, L., Tack, F., Ruhtz, T., Merlaud, A., Van Damme, M., Van Roozendael, M., Schuettemeyer, D., and Coheur, P.: Aircraft observations of NH3 from agricultural sources, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14187, https://doi.org/10.5194/egusphere-egu23-14187, 2023.

In-Service Aircraft for a Global Observing System (IAGOS) is a European research infrastructure that uses the infrastructure of commercial aviation to make in-situ measurements of the atmosphere. We present data from the cloud sensing instrument installed on these aircraft between 2011 and 2021. This includes 1000s of flights across the globe that detect the concentration of cloud particles over the range 5-75 um and this provides information about seasonal variation in cloud frequency across different parts of the globe. From these measurements we are able to estimate properties such as Liquid/Ice Water Content (LWC/IWC), The Effective Diameter (ED) and Mean Volume Diameter (MVD).

How to cite: Lloyd, G. and Gallagher, M.: Global measurements of cloud properties using commercial aircraft, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15334, https://doi.org/10.5194/egusphere-egu23-15334, 2023.

Aerosols have important effects on both local and global climate, as well as on clouds and precipitations. We present here some original results of the AErosol RadiatiOn and CLOud in Southern Africa (AEROCLO-sA) field campaign led in Namibia in August and September 2017. This region shows a strong response to climate change and is associated with large uncertainties in climate models. Large amounts of biomass burning aerosols emitted by vegetation fires in Central Africa are transported far over the Namibian deserts and are also detected over the stratocumulus clouds covering the South Atlantic Ocean along the coast of Namibia. Absorbing aerosols above clouds are associated with strong positive direct radiative forcing (warming) that are still underestimated in climate models (De Graaf etal.,2021). The absorption of solar radiation by absorbing above clouds may also cause a warming where the aerosol layer is located. This warming would alter the thermodynamic properties of the atmosphere, which would impact the vertical development of low-level clouds impacting the cloud top height and its brightness.

The airborne field campaign consisted in ten flights performed with the French F-20 Falcon aircraft in this region of interest. Several instruments were involved: the OSIRIS polarimeter, prototype of the next 3MI spaceborne instrument of ESA (Chauvigné etal.,2021), the LNG lidar, an airborne photometer called PLASMA, as well as fluxmeters and dropsondes used to measure thermodynamical quantities, supplemented with in situ aerosol measurements of particles size distribution.

In order to quantify the aerosols radiative impact on the Namibian regional radiative budget, we use an original approach that combines polarimeter and lidar data to derive heating rate of the aerosols. This approach is evaluated during massive transports of biomass burning particles. To calculate this parameter, we use a radiative transfer code and additional meteorological parameters, provided by the dropsondes. We will introduce, the flight of September 8, 2017, aerosol pollution was very important. Emissions and dust were carried along the Namibian coast, and an aerosol plume was observed above a stratocumulus. We will present vertical profiles of heating rates computed in the solar and thermal parts of the spectrum with this technique. Our results indicated particularly strong heating rate values retrieved above clouds due to aerosols, in the order of 8K per day, which is likely to perturbate the dynamic of the below cloud layers.

In order to validate and to quantify this new methodology, we used the flux measurements acquired during loop descents performed during dedicated parts of the flights, which provides unique measurements of flux distribution (upwelling and downwelling) and heating rates in function of the altitude.

Finally, we will discuss the possibility to apply this method to available spaceborne passive and active observations in order to provide the first estimates of heating rate profiles above clouds at global scale.

How to cite: Ventura, M., Waquet, F., Brobgniez, G., Parol, F., Mallet, M., Ferlay, N., Dubovic, O., Goloub, P., Flamant, C., and Formenti, P.: Synergy of active and passive airborne observations for the evaluation of the radiative impacts of aerosols. Application to the AEROCLO-SA field campaign in Namibia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17533, https://doi.org/10.5194/egusphere-egu23-17533, 2023.

Abstract:

Rare earth elements (REEs) are of high economic value owing to their electronic, magnetic, optical, catalytic, and phosphorescent properties, thereby making them an important part of the development of green technology. They exhibit characteristic sharp absorption features in reflectance spectra in the visible-near infrared (VNIR) to short-wave infrared (SWIR) region due to their 4f-4f orbital intra-configurational electronic transitions.

In this study laboratory based close-range imaging spectroscopy techniques are used along with confirmatory geochemical analytical techniques (petrography, ICPMS, SEM and EPMA) to study 20 samples collected from REE-bearing rocks of the Neoproterozoic Siwana Ring Complex (SRC), a collapsed caldera structure situated in Barmer District, Rajasthan (India).

The SRC is an anorogenic, rift-related bimodal volcano-plutonic rock association belonging to the Malani Igneous Suite. It comprises of felsic and basic volcanic lava flows, rhyolite, peralkaline granite, pyroclastics, tuff and later microgranite, aplite and felsite dykes.

The spectral reflectance curves of the samples collected using an ASD FieldSpec4 (350-2500 nm) exhibit characteristic absorption dips at 439, 491, 580, 740 and 800 nm indicating the presence of Nd³⁺. Other major absorption dips are attributed to the presence of Sm³⁺, U⁴⁺, etc. Various combinations of absorption features in the VIS-SWIR region indicate the presence of minerals like biotite, epidote, chlorite, nontronite, goethite, and REE fluorocarbonates. The Fourier Transform Infrared (FTIR) spectra of the samples collected using a Thermo Fisher Scientific Nicolet 6700 (400-4000 cm^-1) show symmetric and asymmetric bending and stretching vibration features of Si-O, P-O and O-H bonds, which are diagnostic of minerals like aegirine, riebeckite, and REE minerals like monazite apart from other major silicate minerals like quartz and feldspar. The presence of these minerals is confirmed by mineral chemistry, bulk and trace element data.

The observations from the spectroscopic studies seem to correlate well with data obtained from various geochemical analyses. This study provides spectroscopic information on the rocks from SRC for the first time. It shows the proficiency of spectroscopic studies as a cost-effective and non-destructive technique for the identification of REE minerals which can be used before detailed geochemical and mineralogical studies as well as future exploration.

Keywords: Siwana Ring Complex, Spectroscopy, REE

Abbreviations:

ASD – Analytical Spectral Devices, Inc.

EPMA – Electron Probe Micro Analyzer

FTIR – Fourier Transform Infrared

ICPMS – Inductively Coupled Plasma Mass Spectrometry

REE – Rare Earth Elements

SRC – Siwana Ring Complex

SWIR – Short Wave Infrared

VNIR – Visible Near Infrared

How to cite: Imran, S., Goswami, A., Saikia, A., Kumar Rai, H., and Jyoti Barman, B.: Spectroscopic Studies and Confirmatory Geochemical Analyses of Rare Earth Element Bearing Rocks from the Neoproterozoic Siwana Ring Complex, Rajasthan, India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-71, https://doi.org/10.5194/egusphere-egu23-71, 2023.

Recently, hyperspectral datasets recognized a great interest in mineral exploration studies due to their high accuracy in detecting and mapping hydrothermal alteration minerals. Remote and mountainous regions are hardly accessible by geologists, while the spectral richness of imaging spectroscopy could provide detailed information about geology/mineralogy without having a direct contact with the ground surface. The Kerdous inlier in the Anti-Atlas belt of Morocco is recognized by several occurrences of Cu, Pb, Zn Au, Ag, and Mn mineral deposits. This study is carried out in Eastern Kerdous where the abandoned Idikel mine occurs in order to perform a high-resolution mineral potential map using Gamma-Fuzzy logic approach with twenty HyMap-derived layers. The HyMap-based thematic layers were generated using Directed Principal Component Analysis (DPCA), Relative Absorption Band Depth (RBD), and the Mixture Tuned Matched Filtering (MTMF) for pixel/sub-pixel mineral mapping. The hydrothermally altered regions within the study area reveal several Minerals/Mineral mixtures of hematite, illite, kaolinite, montmorillonite, muscovite, topaz, dolomite, and pyrophyllite. Then, the line density map extracted automatically from the HyMap data image was also integrated. The findings of the image processing were validated using field investigation, petrographic, and XRD analysis. This study demonstrates the great potential of the present research methodology and HyMap as a tool for mineral exploitation in similar areas in Morocco's western Anti-Atlas belt.

How to cite: Hajaj, S., El Harti, A., Jellouli, A., Beiranvand Pour, A., Mnissar Himyari, S., Hamzaoui, A., Khalil Bensalah, M., Benaouis, N., and Hashim, M.: HyMap airborne imaging spectroscopy for mineral potential mapping of cupriferous mineralization in a semi-arid region based on pixel/sub-pixel hydrothermal alteration minerals mapping – A case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1642, https://doi.org/10.5194/egusphere-egu23-1642, 2023.

Underground mining is increasing in Korea, primarily due to the depletion of high quality mineral resources from surface open pit mining, and also due to the fact that environmental regulations are gradually tightened and strengthened. For sustainable mine design, safety and environmental issues are the most important factors forcing more specified and systematic guidelines to secure the stability of the mine openings and adits. However, with complex geological settings and various types of rock discontinuities, a geological mapping process to analyze the behavior of fractured rockmass is generally time-consuming. Information on the geologic structures are often collected by visual observation and analyzed based on two-dimensional drawings. Even worse, very limited and unrepresentative data are collected specially at operating mines leading to unreliable conclusions. Hence, construction of three-dimensional hydrogeological models adopting sophisticated surveying techniques has become a routine site investigation process. Laser scanners of high-end specifications are widely used in Korea. In this study, the Trimble X7 with automatic calibration and in-field registration capability has been used to collect accurate geospatial information at an underground limestone mine adopting the room-and-pillar method, with three drifts 9~12m wide and 6m high. For the two pillars of major stability concern, laser scanning was performed to obtain point-cloud data from which a total of 581 discontinuities were extracted. A discrete fracture network was simulated and the stability was evaluated based on the safety factor and displacement using a numerical model.

How to cite: Baek, H. and Kim, D.: Application of the 3-D laser scanning method for assessing the stability of fractured rockmass at an underground limestone mine in Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1750, https://doi.org/10.5194/egusphere-egu23-1750, 2023.

Rare earth elements (REE) have been a focus of global interest because of their irreplaceable role in developing “low carbon” technologies. The Bayan Obo is the world’s largest REE deposit, but its genesis is still highly debated. It is considered to have a close genetic association with carbonatite due to the presence of the carbonatite dykes around the orefield, as well as the geochemical similarities between these dykes and the orebody. However, the evolution of the carbonatite dykes and their REE mineralization are still poorly understood, hindering the interpretation of the genesis of the deposit. More than 100 carbonatite dykes have been found within the area of 0-3.5km nearby the orebodies of the deposit. These dykes show significant variations in mineralogy and geochemistry and were classified into dolomite (DC) and calcite carbonatite (CC). The rocks show an evolutionary sequence from DC to CC, and their corresponding REE contents increased remarkably, with the latter having very high REE content (REE₂O₃ up to 20 wt. %). The DC is composed of coarse-grained dolomite, magnetite, calcite, and apatite without apparent REE mineralization. The medium-grained calcites, and significant amounts of REE minerals, such as monazite, bastnäsite, and synchysite, make up CC. The REE minerals have a close relationship with barite, quartz, and aegirine. The REE patterns of dolomite and calcite in DC showed a steep negative slope with a strong LREE enrichment. In contrast, the calcite from CC has a near-flat REE pattern enriched in both LREE and HREE. Besides, apatite and magnetite in CC are characterized by strong REE enrichment compared to those from DC. Based on detailed petrology, mineralogy, and element geochemistry, we propose that strong fractional crystallization of initial carbonatitic melts led the REE enriched in the residual melt/fluid to form REE mineralization. In addition, sulfate, alkalis, and silica components play an important role in REE transportation and precipitation.

How to cite: Yang, J. and Song, W.: Mineralogy, major and trace element geochemistry of rock-forming and rare earth minerals in the Bayan Obo (China) carbonatite dykes: implications for REE mineralization, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2318, https://doi.org/10.5194/egusphere-egu23-2318, 2023.

The increasing global demand for the rare earth elements (REE), that are critical for green energy production, justifies the necessity of understanding REE ore formation processes [1]. The main type of REE mineralization is mostly found in association with carbonatites and alkaline rocks [1,2]. In addition, in some cases the REE can also reach economical levels in secondary products called supergene REE resources [3]. Primary ore mineralizations mostly are composed of mineral phases that are highly unstable and easily soluble in the near-surface conditions in time. The secondary concentration of the REE in weathering regolith into economic deposits is more favourable than those in primary igneous rocks. As the main source of global heavy-REE, weathering deposits in southern China are the most studied ores of this type [4]. Recently, because of the recent surge in REE deposit exploration and their geological importance, other potentially similar deposits are being studied worldwide. Most of these works focus on mineralogical and elemental aspects of these systems. However, those weathering (in cooperation with alteration) systems are complex and a lot of questions on their formation remain unanswered.

In this work, we focus on the isotopic characterization of regolith hosted REE deposits. To better understand their formation, we utilize stable ⁸⁸Sr/⁸⁶Sr and radiogenic ⁸⁷Sr/⁸⁶Sr ratios, which have been used widely in understanding chemical weathering [5]. Mainly controlled by the incongruent weathering of primary minerals, Sr isotopes can help to identify the sources involved and the main factors affecting regolith hosted REE deposit formation. Strontium is especially important because, as Ca and K, it occurs in different REE-bearing primary and secondary minerals such as carbonates, ancylite, apatite, clays etc.

We will present different regolith profiles’ Sr isotopic data from Asia and Africa. Combining with the elemental and mineralogical data, we will devise a formation model for regolith hosted REE deposits.

References: [1] Goodenough et al. (2016) Ore Geo. Rev., 72, 838. [2] Chakhmouradian & Zaitsev (2012) Elements 8, 347. [3] Estrade et al. (2019) Ore Geo. Rev., 112, 103027. [4] Li et al. (2019) Econ. Geol., 114, 541. [5] Pett-Ridge et al. (2009) GCA, 73, 25.

How to cite: Pourkhorsandi, H., Debaille, V., Decrée, S., de Jong, J., Yaraghi, A., Ndzana, G., Smith, M., Goodenough, K., and Kynický, J.: Radiogenic and stable Sr isotope geochemistry of regolith hosted REE deposits: a preliminary report, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3180, https://doi.org/10.5194/egusphere-egu23-3180, 2023.

Gamma ray is routinely used for correlation, evaluation or classification of minerals and rocks on continent and ocean. Using natural gamma radiation (NGR) derived from Integrated Ocean Drilling Program (IODP) and Ocean Drilling Program (ODP), this study focuses on the correlation between lithology and REE (Rare Earth Element)-bearing sediments in two deep-sea areas, IODP Expedition 329 in the Southwest Pacific and ODP Leg 199 Sites in the Northeast Pacific basins, where values of the REEs are abundant. Deep-sea sediments are consisting mainly of clays, calcareous oozes and siliceous oozes. As a result of the correlation, the REEs prefer to the clays rather than oozes and high values of the REEs correspond with intervals of the clays where the upper sediments (0–70 mbsf) are. The clays show relatively high values of the gamma radiation and the differences between significant elements (Th, U and K) for gamma radiation, derived from geochemical analysis at every site, show two trends reflecting characteristics of regions. Therefore we suggest that the gamma radiation is fully useful for detecting REEs in the deep-sea sediments and plays a role as a predictable tool for finding quantitative REEs. 

How to cite: Lee, C., Kim, Y., Kim, Y.-M., Hong, S. K., and Hong, S.-H.: Gamma radiation for rare earth elements (REEs) in deep-sea sediments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4661, https://doi.org/10.5194/egusphere-egu23-4661, 2023.

Carbonatites are known to host over 95% of light rare earth element (REE) resource, and the REEs are commonly hosted in minerals with well-established extraction methods. Most REE mineralized carbonatites are associated with hydrothermal alteration/recrystallization. Identifying the source composition and role of recrystallization is crucial for understanding the formation of the giant carbonatite-associated REE deposit. Here we report the first in-situ carbon and magnesium isotopic compositions for the hosting dolomite in the Bayan Obo deposit.

In-situ carbon isotope analyses of dolomite from the coarse-grained (CM), fine-grained (FM) and heterogeneous-grained (HM) samples show a wide range of δ¹³C values (-5.19‰ to 2.08‰), which is distinct from the common mantle-derived carbonatite and slightly overlaps the range of sedimentary carbonate. CM dolomite displays almost homogeneous carbon isotope compositions (δ¹³C=-1.29‰ to 0.16‰) with the average δ¹³C of -0.82‰. Recrystallized dolomites from both FM and HM samples vary greatly, and FM dolomite generally displays a heavier δ¹³C range (-3.94‰ to 2.08‰) compared to that for HM dolomite (-5.19‰ to 0.64‰). CM dolomite also shows relative consistent Mg isotope compositions in the range of -0.27‰ to 0.05‰ with an average of -0.10‰, which is similar to the mantle value. δ²⁶Mg values of FM and HM dolomites vary greatly from -1.18‰ to 0.06% with averages of -0.40‰ and -0.32‰, which are lighter compared to that of CM dolomite. The recrystallized dolomites (FM and HM) are characterized by depleted light REE (LREE) and increased Pb/Ce_N features compared to the pristine dolomite (CM). Moreover, the LREE depletion and Pb/Ce_N increase correlate with the lighter Mg isotope compositions. The highly variable C isotopes recorded by FM and HM dolomites (lighter or heavier compared to the pristine dolomite) involve both recrystallization and degassing. The combined in-situ Mg and C isotope compositions of the pristine dolomite suggest the Bayan Obo carbonatite sourced from the mantle previously fertilized by fluids derived from the carbonate-bearing subduction slab.

How to cite: Chen, W., Yang, F., and Lu, J.: In-situ C and Mg isotopes of dolomite from the giant Bayan Obo REE deposit: Implications for recrystallization and recycled carbonate in the source, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4823, https://doi.org/10.5194/egusphere-egu23-4823, 2023.

As the world's largest rare earth elements (REEs) deposit, the giant Bayan Obo deposit accounts for more than one third of the world's REEs resources. Fenitization is an alkali metasomatism that widely occurs around the carbonatite dykes at Bayan Obo and recent studies reveal huge quantities of REEs could be transferred from the alkaline magma to fenite (Sokół et al., 2022). However, the contribution of fenitization to REE mineralization at Bayan Obo remains unclear. Here, we present bulk rock chemical compositions, in-situ chemical and C-Sr isotopic investigations of calcite and apatite together with Th-Pb ages of monazite, aiming to provide new constraints on REE mineralization during fenitization.

Carbonatite at Wu dyke is mainly composed of calcite, aegirine and barite associated with REE minerals dominated by bastnasite and parisite, which intruded into the surrounding wall rocks of quartz conglomerate. The associated fenites include the close Na-fenite and faraway K-fenite. Na-fenite contains calcite, riebeckite, aegirine and apatite with minor monazite and bastnasite in association with barite. K-fenite consists of K-feldspar and quartz with accessory riebeckite and albite. Both REE and SO₃ contents decrease from the center to the wall rocks. REE are most enriched in the centered carbonatites (up to 7.39 wt%), and Na-fenites also display strong REE enrichment (9876-22492 ppm). Of note, high-grade Na-fenite is characterized by the highest LREE concentrations among fenites, whereas HREE is most enriched in medium-grade Na-fenite. The latter is dominantly controlled by apatite, which hosts abundant HREE (118-677 ppm). Calcite from fenites displays flat REE patterns with more depleted LREE (La/Yb_N=0.28-3.02) compared to that within carbonatite (La/Yb_N=1.66-6.52). Th-Pb ages of monazite from fenites cover a wide range from 420 Ma to 1.27 Ga, which suggests these fenites have also undergone the early Paleozoic hydrothermal alteration. In-situ Sr and C isotope analyses of calcite from carbonatite define a limited range (⁸⁷Sr/⁸⁶Sr=0.70344 to 0.70358 and δ¹³C=-4.36 to -5.1 ‰), which are consistent with a mantle origin . ⁸⁷Sr/⁸⁶Sr and δ¹³C values for calcite within Na-fenite show larger variations of 0.70358 to 0.70620 and -4.92 to -9.87 ‰, respectively. Negative shift in δ¹³C values suggest degassing through the fenitizing reaction of 18CO₃^2-+2Na⁺+3(Mg²⁺,Fe²⁺)+2Fe²⁺+8SiO₂+24H⁺+0.5O₂= Na₂(Mg,Fe²⁺)₃Fe³⁺₂Si₈O₂₂(OH)₂+18CO₂+11H₂O. More radiogenic Sr isotopic compositions of fenites result from both assimilation of wall rocks during fenitization and the redistribution of Sr isotopes among minerals during the Paleozoic hydrothermal alteration.

Carbonatite-exsolved fenitizing fluids result in predominant REE enrichment within Na-fenite accompanying with light and heavy REE mineralization. LREE mineralization is dominated by monazite precipitation, and HREE enrichment is mostly controlled by apatite. Sulfate is an important ligand for REE transportation and mineralization during fenitization. Barite crystallization and simultaneous precipitation of LREE-bearing minerals lead to fenitizing fluids abundant in HREE, promoting the further formation of HREE-rich apatite.

Reference:

Sokół K., Finch A.A., Hutchison W., et al., 2022. Quantifying metasomatic high-feld-strength and rare-earth element transport from alkaline magmas. Geology, https://doi.org/10.1130/G49471.1.

How to cite: Yang, F. and Chen, W.: Fenitization associated with the Wu carbonatite dyke at Bayan Obo (Inner Mongolia, China): Implications for REE mineralization, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5183, https://doi.org/10.5194/egusphere-egu23-5183, 2023.

Karstic bauxite deposits are the main resource of aluminum in Europe and are formed through a combination of weathering, leaching, and deposition processes known as bauxitization. Bauxites have recently been proposed as unconventional resources of rare-earth elements (REE) as well. The studied karstic bauxite deposits are located on the salt-detached Serres Marginals thrust sheet, at the external most unit of the south-central Pyrenees (Catalonia, NE Spain). The Pyrenean bauxites are found overlaying and filling karstic surfaces forming aligned pockets up to several meters thick. These deposits have been mined for more than 20 years and present high variability in SiO₂, Al₂O₃ and Fe₂O₃ contents. Here, we characterize these deposits for the first time by a combination of field geology, XRD, FTIR and XRF to determine their formation, mineralogy, and geochemistry and to understand the causes affecting their compositional variations. Field data indicate that the bauxite deposits fill a paleokarst system affecting Dogger dolostones and/or Tithonian-Berriasian limestones. XRD data indicate that the studied karstic bauxites are mainly composed of Al-rich minerals kaolinite and boehmite, in addition to the Fe-oxide hematite, and lesser amounts of the Ti-oxides rutile and anatase. The detailed study of the FTIR spectra also confirmed the presence of diaspore and dickite. XRF data confirm the presence of varying amounts of Al, Fe and Si in addition to varying low contents of REE. These results suggest that boehmite was formed first during bauxitization and later transformed to diaspore, kaolinite and finally to dickite upon metasomatism. The presence of dickite in faults and fractures provides a direct proof for such fluid circulation. Our results suggest that the mechanisms responsible of the compositional variations in karstic bauxites are rather complex and fall beyond the standard bauxitization processes. The observed metasomatism should be further assessed, since the inferred fluid-rock interactions are susceptible to affect and mobilize REE not only in the south-central Pyrenees karstic bauxites but elsewhere in similar geological settings.

How to cite: Roqué-Rosell, J., Granado, P., Martín-Martín, J. D., Ibáñez-Insa,, J., Pérez Bustos, I., Roca-Miró, R., and Jiménez Franco, A.: The metasomatism affecting karstic bauxites from the south-central Pyrenees, Catalonia (NE Spain) and its implications on the REE geochemistry in similar geological settings., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8008, https://doi.org/10.5194/egusphere-egu23-8008, 2023.

This paper presents the development and implementation of a LIBS (Laser-Induced Breakdown Spectroscopy) system based on a robotic arm for fast chemical characterization of blast hole rock cuttings in open pit mining. The system is designed with an open architecture, allowing for the easy integration of additional sensors such as a spectrophotometer and a magnetic susceptibility meter. The use of the LIBS system significantly reduces the time required to characterize the raw material and obtain a broader characterization, including geological characterization. The preliminary results of this development demonstrate the potential of the LIBS system in improving the efficiency and accuracy of rock characterization in open pit mining operations.

How to cite: Maas, A., Akushika, J., and Arboleda, F.: Blast Hole Rock Cuttings analysis: Design and Implementation of an open Architecture LIBS System, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9090, https://doi.org/10.5194/egusphere-egu23-9090, 2023.

Recently, due to the active spread of electric vehicles, the demand for batteries is increasing fast, and for this reason, the exploration for lithium that is an essential mineral for battery production, is increasing. In Korea, lithium exploration is also being conducted around deposits where lithium was identified in the past. However, most lithium mines are located in very rough terrain, so it is not easy to conduct a surface geological and geophysical exploration. Without considering complex topography, errors may occur in the inversion of surface geophysical exploration data, and in particular, it is necessary to use precise topographic information for the three-dimensional inversion. In this study, we would like to introduce a case study using high-resolution topographic data obtained from a drone-mounted LIDAR in the three-dimensional inversion of surface resistivity and IP data conducted for lithium exploration. The target area is the Boam Mine, located in the Middle East of Korea. Surface geophysical exploration was conducted along a road and ridge of the mountain, which are relatively easy to set up the survey line. Because existing topographic maps that are publically available did not include mining traces related to mining development and topographical changes formed by nearby roads, it is not adequate for the 3D inversion of surface resistivity and IP data. To acquire precise topographical information, aerial photography and LIDAR measurements using drones were performed. A numerical topographic model was constructed using the obtained high-precision DEM (digital elevation map). By applying this to the three-dimensional inversion, the distribution of the underground mineralization zone was estimated. The interpreted results were compared with the existing drilling results performed near the mine. Comparing the two results, drilling surveys using only surface geological information proceeded in the direction in which the mineralization zone did not develop. Drone LIDAR measurement is a costly exploration method and is difficult to use actively at all exploration sites. However, if three-dimensional inversion is required where the surface topography is very complex, as in this survey area, it could give more reliable inversion results.

How to cite: Son, J., Kim, C., and Bang, E.: Three-dimensional interpretation of DC resistivity/IP survey for Lithium exploration using high-precision topographic information from drone-mounted LIDAR., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10680, https://doi.org/10.5194/egusphere-egu23-10680, 2023.

Recently, the demands for energy storage minerals such as vanadium and lithium are increasing as the use of the batteries for electrical vehicles has increased. Vanadium is one of the energy storage minerals occurred in Korea. In this study, vanadium mineralized zones of the ore deposit, named as Gwanin deposit, was investigated using geophysical exploration techniques. The mineralized zone is known as vanadiferous titanomagnetite (VTM) deposit, originated from pre-cambrian igneous intrusions (850-870 m.a.), located in the northwest region of Korea. Since the vanadium has occurred along with magnetite (low electrical resistivity and high magnetic susceptibility) in the study area, geophysical exploration techniques such as magnetic and electrical resistivity surveys were employed. For magnetic exploration, the drone magnetic survey technique was used since it provides more precise and higher resolution data than any other aerial magnetic exploration techniques for relatively small and mountainous areas. In addition, electrical resistivity data were obtained from the six survey lines in the study area. 3D inversion was performed with magnetic and resistivity data. The anomaly zones of low electrical resistivities and high magnetic susceptibilities were interpreted as VTM mineralized zones from the two different inversion results. The mineralized zones were identified from the drilling investigation for overlapping locations of the anomaly zones. The results of the study have shown that magnetic and electrical resistivity techniques are very effective tools for exploring ore deposits of vanadium resource accompanied with magnetite. In the future, drone magnetic exploration technique combined with other (surface) geophysical exploration techniques would provide more effective results of precise geophysical surveys for relatively small and mountainous areas with similar ore deposit environments.

How to cite: Kim, C., Son, J., Bang, E., Park, G., and Kim, B.: Investigations of Vanadiferous Titanomagnetite Deposit using Drone Magnetic and Electrical Resistivity Surveys in Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10689, https://doi.org/10.5194/egusphere-egu23-10689, 2023.

Apatite with high REE content is common in alkaline rocks, carbonatites and products of hydrothermal processes. The REE concentrations could enter mineral structure by different substitution mechanisms (Fleet et al., 2000) and the factors controlling the composition of high-REE apatite are not completely understood. New experimental data (Stepanov et al., 2023) show that at 800 °C and 10 kbar apatite crystalizing from felsic melt with addition of NaCl contains 14 wt.% ΣREEOx and coexists with britholite (37.2 wt.% ΣREEOx). The results suggest that equilibrium has been established during the run and both apatite and britholite contained REE in [Si4+REE3+] to [Ca2+P5+] solid solution, whereas the coupled substitution [Na1+REE3+] to [2Ca2+] was insignificant despite crystallisation from an alkaline, Na-rich melt. Coupling of the new experimental data allowed to constrain the width of the miscibility gap between apatite and britholite, and suggest complete miscibility between apatite and britholite above 950 °C. The substitution [Na1+REE3+] apparently develops mainly in apatite replacement reactions. Therefore, REE content and substitution mechanisms could be useful tools for interpretation of magmatic and metasomatic/hydrothermal associations in alkaline volcanic and plutonic rocks.
References 
Fleet, M., Liu, X., Pan, Y., 2000. Rare-earth elements in chlorapatite [Ca-10(PO4)(6)Cl-2]: Uptake, site preference, and degradation of monoclinic structure. American Mineralogist 85, 1437–1446.
Stepanov, A.S., Zhukova, I.A., Jiang, S.-Y., 2023. Experimental constraints on miscibility gap and partitioning between britholite and chlorapatite in alkaline melt. American Mineralogist.

How to cite: Zhukova, I. and Stepanov, A.: Experimental data on REE in apatite in high-REE environments: distinguishing magmatic and metasomatic compositions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11255, https://doi.org/10.5194/egusphere-egu23-11255, 2023.

Future mining will increasingly require rapid and informed decisions to optimise ore extraction and valuation. In this context, the use of hyperspectral imaging has been proven to be effective for geological mapping in surface mining operations. The potential of hyperspectral methods in underground mining environments, however, remains underexplored due to challenges associated with illumination and surface water. Our contribution addresses this gap by evaluating different lighting setups and the effect of moisture on the spectral quality of hyperspectral data in a laboratory setup. We also compared three commercially available, visible-near infrared to shortwave infrared sensors to assess their suitability for underground hyperspectral scanning. As a demonstration, we acquired hyperspectral data from three adjacent outcrops in the visitor’s mine of Zinnwald, Germany, where rocks of a Late Variscan Sn-W-Li greisen-type deposit are exposed in representative underground mining conditions. A photogrammetric 3D digital outcrop model was used to correct for illumination effects in the data. We then estimated mineral abundance and lithium content across the mine face employing an adapted workflow that combines quantitative XRD measurements with hyperspectral unmixing techniques. Laser-induced breakdown spectroscopy was used to validate the results. While there are still challenges to overcome, this study proves that hyperspectral imaging techniques can be applied underground to yield rapid and accurate geological information. This application will pave the way for the safe, digital and automated underground mine of the future.

How to cite: Kirsch, M., Mavroudi, M., Thiele, S., Lorenz, S., Tusa, L., Booysen, R., Herrmann, E., Fatihi, A., Möckel, R., Dittrich, T., and Gloaguen, R.: Hyperspectral mineral mapping for underground mining, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11997, https://doi.org/10.5194/egusphere-egu23-11997, 2023.

ROBOMINERS (Bio-Inspired, Modular and Reconfigurable Robot Miners, Grant Agreement No. 820971, http://www.robominers.eu) is a European project funded by the European Commission's Horizon 2020 Framework Programme. The project aims to test and demonstrate new mining and sensing technologies on a small robot-miner prototype (~1-2T) designed to target unconventional and uneconomical mineral deposits (technology readiness level 4 to 5) (Lopez and al. 2020).

As part of the ROBOMINERS sensor array development, a set of mineralogical and geophysical sensors are designed to provide the necessary data to achieve a “selective mining” ability of the miner to reduce mining waste production and increase productivity of a small mining machine. To achieve this, the robot should have the ability to react and adapt in real time to geological changes as it progresses through a mineralized body. This study focuses on a set of compact sensors designed for ultrahigh-resilience and continuous operation in high pressure/vibrations/temperature environment. They are based on reflectance/fluorescence measurements in the visible/near infrared range, using a broadband light source (tungsten-halogen lamps) in reflectance mode and 365nm UV LED in fluorescence mode. 

The ROBOMINERS reflectance/fluorescence spectrometer “Mk1” was developed in collaboration with Taltech University. The spectrometer is built around a monolithic spectrometer (Hamamatsu C12800MA and a wifi capable microcontroller (Arduino RP2040 Connect).. As the ROBOMINERS prototype will be operated by ROS2 (Robotic Operating System v2 - https://www.ros.org/ ), we decided to implement a Micro-ROS publisher on the microcontroller.

The first field trials of the sensor have been carried out in the entrance of abandoned mine (baryte and lead mine, Ave-et-Auffe, Belgium), with the sensor integrated directly in the propulsion mechanism of the “RM3”’ ROBOMINERS prototype. This test allowed to demonstrate the immunity of the sensors to  to shocks, water and dust with no measurable de-calibration of the spectrometer.

References.

Lopes, B. Bodo, C. Rossi, S. Henley, G. Žibret, A. Kot-Niewiadomska, V. Correia, Advances in Geosciences, Volume 54, 2020, 99–108

How to cite: Burlet, C., Stasi, G., Godon, S., Gkliva, R., Piho, L., and Ristolainen, A.: ROBOMINERS resilient reflectance/fluorescence spectrometers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12056, https://doi.org/10.5194/egusphere-egu23-12056, 2023.

The rare earth elements (REE), and in particular neodymium and dysprosium, are essential for the development of renewable energy. At present the REE are sourced from either low concentration weathered granitoid (ion adsorption clay) deposits in southern China, or from high concentration carbonatite-related deposits [1], especially the World’s dominant REE mine at Bayan Obo, China, but also including the Mt Weld weathered carbonatite, Australia. Weathered carbonatites (e.g. Tomtor, Russia; Mount Weld, Australia) are some of the world’s highest grade REE deposits. As part of the NERC Global Partnerships Seedcorn fund project WREED, we have carried out preliminary investigations in weathering products from carbonatite hosted REE deposits. Three end member deposit styles can be identified – in situ residual deposits, where carbonate dissolution has generated primary REE mineral enrichment on palaeosurfaces or in karst; supergene enrichment from dissolution and reprecipitation of REE phosphates and fluorcarbonates forming hydrated phosphates or authigenic carbonate minerals; clay and oxide caps (either from in situ weathering or from soil transport from surrounding rocks) that may hold the REE adsorbed to mineral surfaces (c.f. the ion adsorption deposits). High grade weathered carbonatite deposits typically consist of supergene horizons, that may be phosphate-rich due to dissolution and re-precipitation of apatite and monazite during the weathering process (Mount Weld [2][3]), overlain by later sediments that may be REE enriched by accumulation of residual minerals (e.g. Tomtor [4]). The mineralogy of the ore zone is linked to, but distinct from, the unweathered carbonatite rock, and includes phosphates, crandallite-group minerals, carbonates and fluorcarbonates and oxides. We have carried out leaching studies, SEM examination and XPS characterisation of soil and weathered rock samples from a range of deposits. Residual and supergene processes can result in enrichments up to 100x times bedrock concentrations, with residual enrichments in particular hosted in monazite and bastnäsite. Supergene enrichment results in more complex mineralogy which may present processing challenges. Clay-rich soils have much lower REE concentrations. However, sequential leaching studies demonstrate that a significant proportion of REE are present at trace levels in the oxide fraction in residual and supergene deposits. In clay caps the easily leachable fraction of REE matches that of ion adsorption deposits and may represent a potentially easily extractable resource.

References

[1] Wall and Chakhmouradian, 2012, Elements 8, 333-340;

[2] Duncan and Willett, 1990, Geology of Mineral Deposits of Australia pp. 591-597;

[3] Lottermoser, 1990, Lithos 24, 151-167;

[4] Kravchenko and Pokrovsky, 1995, Econ. Geol. 90, 676-689;

How to cite: Smith, M., Beard, C., Watkins, I., Broom-Fendley, S., Wall, F., Cheng, X., Liu, Y., Chen, W., and Kynicky, J.: The surface chemistry of carbonatite soils: Implications for REE resources., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13081, https://doi.org/10.5194/egusphere-egu23-13081, 2023.

Geological face mapping is a frequently recurring task in mining operations, the results of which have an immediate influence on the mines’ profitability, safety, and environmental impact. Hyperspectral imaging is an increasingly applied technology to improve the efficiency and accuracy of mapping tasks. The rapid and non-destructive acquisition of spectral material properties allows meaningful material information such as mineralogical surface composition to be obtained in a safe and efficient manner. The fusion product of backprojected hyperspectral data with 3D surface information (so-called “hyperclouds”) further enhances the data value by enabling easier data correction, integration, and implementation into digital archives and models. Mining environments, however, remain a challenge for operational hyperspectral mapping, particularly underground where inadequate lighting, access, and safety of operation make data collection difficult. Data processing and interpretation require expert knowledge and are typically performed semi-manually and offline. To be economically viable in such mining environments, the hypercloud technology has to mature toward autonomy and real-time delivery of results. In recent years, terrestrial autonomous platforms have entered the market that are suited to the challenging conditions of underground mining and can maneuver and navigate even in confined, uneven, and poorly lit environments. They provide optimal carriers for hyperspectral sensors, which have simultaneously evolved into lighter, faster, and more robust devices. However, implementing hyperspectral sensors as payload for terrestrial autonomous robots remains challenging, especially in terms of  technical compatibility, ensuring data quality under complex conditions,  and processing large amounts of data quickly and autonomously. In our contribution, we demonstrate the potential of autonomous terrestrial robots combined with hyperspectral technology and advanced data processing for the automation of geological mapping. We present results of hyperspectral data acquisition using an autonomous robotic platform in a confined underground mining environment and discuss strategies for adapted sensor design, autonomous validation, real-time hypercloud processing, and enhanced autonomous navigation supported by hyperspectral information. 

How to cite: Lorenz, S., Kirsch, M., Fuchs, M., Thiele, S., and Gloaguen, R.: Robot-aided autonomous hyperspectral mapping in mining environments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13899, https://doi.org/10.5194/egusphere-egu23-13899, 2023.

Mineral resource exploration techniques and methodologies have undergone a very strong development in the last decade: e.g. portable and higher sensitive equipment, robotized exploration equipment, and tools for processing and interpreting of large, multidimensional datasets. In order to meeti the raw materials policy goals of the EU, these technologies should also be incorporated in higher education (Mádai, 2022).

TIMREX is a new EIT-Labelled joint master's program to train geoscience students focusing on innovative raw materials prospecting and exploration methods. The consortium consists of four academic partners – University of Miskolc, Hungary, University of Zagreb, Croatia, Wroclaw University of Science and Technology, Poland and Luleå University of Technology, Sweden. All four academic partners run their mineral exploration-focussed, geoscience engineering-type master programmes which comprise the ground for the joint master programme. Participating Universities are located within Fennoscandian, Fore-Sudetic and Tethyan/Carpathian-Balkan metallogenic belts hosting numerous primary, secondary and critical mineral resources essential for green transition of Europe. Scandinavian and West Balkan countries holds first and second place according to total mineral resources investments in Europe (data from 2019).

The TIMREX consortium incorporates eight non-academic partners who are at the frontier of mineral resource prospecting and exploration equipment and methodology development in the EU. They represent leading European mining companies such as Boliden Mineral and KGHM, but also SMEs and start-ups such as the Unexmin Georobotics (UGR) and the Geogold Kárpátia Ltd., as well as research institutes such as the Portuguese INESC TEC and the Slovenian Geological Survey (GeoZS).

Non-academic partners are actively involved in the TIMREX joint programme as trainers in field programs, internship mentors or thesis topic providers. Students of the programme can join research and development work at the partners. Examples are development of underwater robotized exploration methodologies (INESC TEC, UGR), drone-based multispectral surveys and complex dataset evaluation (Boliden, KGHM Cuprum, GeoZS, Geogold). The European Federation of Geologists provides a wider network of European prospectors and explorers to the joint programme and contributes to teaching of entrepreneurial skills. Therefore, TIMREX directly address major gaps of the Raw Materials sector: limited availability of qualified technical, scientific and managerial personnel involved in the whole mineral cycle (Borojević Šoštarić et al., 2022) as well as lack of generic skills crucial for increasing the innovation capacity of universities and their graduates (Grgasović and Borojević Šoštarić, 2021).

Borojević Šoštarić, S., Giannakopoulou, S., Adam, K. i Mileusnić, M. (2022). The future of mining in the Adria region: current status, SWOT and Gap analysis of the mineral sector. Geologia Croatica, 75 (Special issue), 317-334. https://doi.org/10.4154/gc.2022.26

Grgasović, P.; Šoštarić, S.B. (2021) Systematic Development of Generic Skills to Enhance Innovation Capacity of Eastern and Southeastern European Universities. Mater. Proc.

5, 99, 1-7. https://doi.org/10.3390/ materproc2021005099

Mádai F. (2022) Competence requirements of innovation and entrepreneurship oriented training programmes for the mineral exploration sector. In: Veresné Somosi M.; Lipták K.; Harangozó  Zs.(eds) "Mérleg és Kihívások - Fenntarthatóság" Miskolci Egyetem Gazdaságtudományi Kar (2022) pp. 537-547

How to cite: Madai, F., Borojević Šoštarić, S., Paszkowska, G., and Jansson, N.: TIMREX – a European joint master programme to implement innovative mineral exploration achievements in geoscience education, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15053, https://doi.org/10.5194/egusphere-egu23-15053, 2023.

How to cite: Gemmell, C., Currie, D., Neill, I., Einsle, J., and MacRae, C.: Re-evaluating Caledonian magmatism and associated base metal mineralisation: a case study of the Black Stockarton Moor porphyry copper system, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15445, https://doi.org/10.5194/egusphere-egu23-15445, 2023.

To face the growing demand for raw materials, the discovery of new mineral deposits is essential for the future. Geophysical methods, and in particular electrical and electromagnetic tools, have an important role in mineral exploration. Recently, new technological developments made possible targetting deeper ore bodies and large areas with logistical challenges. We use the Deep Electrical Resistivity Tomography (DERT) method to investigate its application in mineral exploration. In particular, we use the Fullwaver technology developed by IRIS Instruments to study the full 3D resistive structure of the Calamita distal Fe-skarn deposit, Elba Island, Italy. This innovative hardware allows a full 3D deployment of autonomous and cable-less receivers and contrasts with traditional resistivity methods by its easy set-up and applicability in difficult contexts.

In November 2022, a 3D DERT survey has been carried out to investigate the Calamita deposit, consisting of massive magnetite-hematite ore bodies hosted in marbles overlaying micaschists of Tuscan Units. Skarn mineralogy/geochemistry and fluid inclusion characteristics suggest a magmatic source for the mineralizing fluids. 148 current injections have been performed on 48 receivers over an area of 2km² with the aim to reach exploration depths ranging from 600 m to 700 m. Geophysical data were combined with a high-resolution 3D Digital Elevation Model acquired by standard and thermal drone imagery.

The 3D inverted resistivity and induced polarization models match with the surface geology and shallow exploration drill hole data and highlight the architecture of Calamita deposit. Strong resistivity contrasts reveal the presence of sub-vertical conductive and chargeable pipes connecting the different skarn bodies at depth, interpreted to represent the paleo-hydrothermal upflow zones. The pipes point towards the inferred cupola of a magmatic intrusion that potentially triggered the formation of the ore deposit. High chargeability anomalies suggest the presence of hidden massive ore bodies and disseminated mineralisation on the flanks of the system.

DERT has the potential to investigate and explore mineral deposits in full 3D, with high sensitivity, and in logistically complex settings.

How to cite: Braize, D., Sfalcin, J., Lupi, M., Kouzmanov, K., Dini, A., and Morelli, G.: Deep Electrical Resistivity Tomography as a mineral exploration tool: the Calamita distal Fe-skarn, Elba Island (Italy), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16567, https://doi.org/10.5194/egusphere-egu23-16567, 2023.

Dig_IT project aims to develop a human-centred IIoT platform connecting the mining ecosystem of assets, environment, and humans to increase mining efficiency: saving costs using optimised scheduling, increasing uptime using predictive operation and maintenance, identifying new revenue opportunities using advanced geological interpretation on exploration mining phase. To address industry needs of minimising accidents, optimising production processes and reducing costs, intelligent systems will provide real-time insights for the enterprise at all operational levels.

Dig_IT follows a market need & technology offer approach aiming at covering all aspects of technical, industrial and business requirements towards a sustainable future in mining. The project’s value chain and concept has been built with the utmost objective to provide new solutions addressing the needs for safety, efficiency and sustainability, bringing innovative and competitive solutions to the mining business, face future challenges regarding standards and legislation, and spread the knowledge to as many sectors of the European extractive industry as possible.

The project aims to achieve several objectives: design and validate a smart Industrial Internet of Things platform to improving efficiency and sustainability of mining operations, achieving on-line measurements of asset-bound mining operations and online distributed measurements for broad area sustainability and occupational work environment, and Big Data optimisation through improving data quality. Furthermore, the project aims to develop Digital Twins of the physical mine entities, systems and processes, a Smart Garment and an Intelligent Toolbox for mining personnel sensing OHSE parameters, a Decision Support System and a Predictive Operation System.

How to cite: Grimani, D., Bortoloni, L., Vallocchia, D., Garcia Camprubi, M., and de Paz, D.: Dig_IT – A human-centred Internet of Things platform for the sustainable digital mine of the future, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17258, https://doi.org/10.5194/egusphere-egu23-17258, 2023.

The UX-2 robot of the UNEXMIN technology represents the newest generation of underwater explorers capable of operating in flooded mines and other closed underwater environments meanwhile providing geoscientific information. The technology was developed by an international team of scientists during the UNEXMIN (https://www.unexmin.eu/) Horizon 2020 project (2016–2019) and the UNEXUP (https://unexup.eu/) EIT RawMaterials project (2020–2022). The concept was proven in various environments and the first generation of robots was built in the UNEXMIN project. Besides technological upgrades, the UNEXUP project was focusing also on marketing and commercialization thru UNEXMIN Georobotics Ltd. (https://unexmin-georobotics.com/), the spin-off of the consortium.

The technology proved its capabilities at numerous flooded sites in various harsh environments during the last years including, abandoned mines, caves, historical sites and even drinking water facilities.

Although very bad visibility was observed in the South Crofty mine, Camborne (UK), the robot could manoeuvre down to -300 m and investigate a narrow shaft relying mainly on sonar-based navigation.

The Csór water well, the main drinking source of Székesfehérvár (Hungary) was another location where the UX technology proved its usefulness and 3D-mapped the well with centimetre accuracy for reconstruction purposes.

In August of 2022, the UX robot created a 3D topography map and continuous water parameter measurements further exploring the flooded karstic cave Hranice Abyss (Czech Republic) down to -450 m – setting up the current word depth record.

Even remote-control and full autonomy were demonstrated in Kőbánya-mine, Budapest, Hungary. During the remote-control test, the Budapest team launched the robot, but the underwater robot operation was done from INESCTEC, Portugal.

Ecton copper mine (UK) used to be the deepest mine of its age in the 18th century, closed and partially flooded for more than 160 years. Now it is a listed National Monument in the UK and is under strict protection within a site of special scientific interest. Here the UX robots proved their value in discovering new workings, connections, and technological solutions helping the archaeologists which could not be recovered by other methods as well as elucidating the geological structure.

The salt mine of Solotvyno, Ukraine was a demanding challenge as the UX robot had to be capable of operating and measuring in freshwater as well as in fully saturated (ca. 330g/l) brine with 1.25 g/cm³ density, which was located below a freshwater layer.

The abandoned fluorspar mine of Würmtal, Pforzheim, Germany was the last site visited within the frame of the UNEXUP project where the UX robot revealed its unique capabilities by exploring a large part of the flooded workings. More than 3 km was covered laterally in a single dive down to the fluorspar vein, and colour- and UV-images of the ore were delivered successfully. UX robot also brought back data, helping to assess the stability of the walls.

The UNEXMIN project was funded by the European Union thru the Horizon 2020 research and innovation programme under the no. 690008 grant agreement.

The UNEXUP project was funded partially by the European Union thru EIT RawMaterials no. 19160.

How to cite: Zajzon, N., Topa, B. A., Papp, R. Z., Aaltonen, J., Almeida, J., Bodo, B., Henley, S., Pinto, M., and Zibret, G.: Underwater measurements with UX robots; a new and available tool developed by UNEXUP, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17279, https://doi.org/10.5194/egusphere-egu23-17279, 2023.

The radio emissions nicknamed "caterpillars" are believed to be a special form of Saturn kilometric radiation (SKR) at low to very low frequencies. They are coarse spectral structures lasting for several hours mostly below 40 kHz, and their constant central frequency with a typical bandwidth of 10-15 kHz makes them look like caterpillars in a time-frequency spectrogram. We found almost 600 caterpillar emissions with the RPWS (Radio and Plasma Wave Science) instrument throughout Cassini's tour around Saturn. We present a statistical investigation of their occurrence with respect to the position of Cassini, their duration, central frequency, bandwidth, polarization, intensity, and connection to SKR at higher frequencies. We also compare their occurrence with the occurrence of SKR low frequency extensions (LFEs) as many of them are found during so-called long LFEs. We will discuss and investigate the reasons for the loss of total polarization of caterpillars, which could be due to wave reflections at the magnetosheath or due to an incoherent superposition of X-mode with O-mode SKR.

How to cite: Fischer, G., Taubenschuss, U., Pisa, D., Lamy, L., Wu, S., Ye, S., Jackman, C., and O'Dwyer, E.: Statistical investigation of SKR caterpillar emissions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2066, https://doi.org/10.5194/egusphere-egu23-2066, 2023.

Discoveries of exo-auroral radio emission in the last two decades have led to an ongoing paradigm shift––many highly circularly polarized intense radio bursts detected in a variety of low-mass stars are likely signatures of auroral activities rather than flare-driven magnetic activities. Such discoveries have opened a new window in probing the magnetic field in stellar/substellar/exoplanetary systems. One of the outstanding challenges in discerning the two scenarios is characterizing the aurora-generating magnetic topologies of the stellar/substellar objects despite their large distances. Thanks to its proximity, the Sun provides much of the detailed context to study radio bursts similar to those in the stellar/substellar regime. A recent imaging spectroscopy observation with the Jansky VLA reveals a new type of radio bursts near a sunspot, which resembles exo-auroral radio emission in the literature both temporally and spectrally. Unlike the planetary aurora scenario, the detected radio signature is identified as electron cyclotron maser (ECM) emission from a sunspot driven by energetic electrons accelerated in flare activities. Comprehensive observations of sunspot auroral radio emissions will not only advance our understanding of the fundamental physical processes of ECM emissions on the Sun but also impose broad implications on stellar/substellar physics and exo-space weather sciences. These efforts will require long-term monitoring by a solar-dedicated, broad bandwidth radio telescope capable of imaging the Sun in dual circular polarization with a high image dynamic range and subsecond time resolution, which is still lacking. In this talk, after a brief introduction to ECM emissions from stars and the Sun, I will discuss the technical requirements in order to make a leap forward in observations of aurora-type ECM emissions from the Sun, and the expected science returns from a superior broadband radio imaging spectropolarimetry capabilities of a next-generation radio heliograph, such as the Frequency Agile Solar Radiotelescope (FASR) concept. 

How to cite: Yu, S., Chen, B., Sharma, R., Bastian, T., Mondal, S., Gary, D., Luo, Y., and Battaglia, M.: Long-Lasting Solar Coherent Radio Bursts and Implications for Solar–Stellar Connection, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2887, https://doi.org/10.5194/egusphere-egu23-2887, 2023.

Type II and III radio bursts are associated with solar eruptive events–CMEs and solar flares. Since radio wave propagation in the interplanetary medium is strongly affected by random electron density fluctuations, radio bursts provide us with a unique diagnostic tool for solar wind remote plasma measurements.  Radio wAve Propagation In thE solaR wind (RAPIER) is a proposal submitted to the Heliophysics Theory, Modeling, Simulations (H-TMS) program, which is a component of the Heliophysics Research Program (NASA). Within this project, we intend to analyze spacecraft data and computer simulations to improve our knowledge of the generation and propagation of type II and III radio bursts and density fluctuations in the inner heliosphere. We will achieve this goal by answering the following science question: “What is the role of solar wind structures on radio burst propagation?” We will study the role of small and large scale density structures on the propagation of radio waves in the solar wind using computer simulations. Specifically, we will focus on disentangling the intrinsic variations in solar radio emissions from propagation effects. We will study the role of scattering by plasma density inhomogeneities on the propagation of radio waves using computer simulations. It allows us to remotely investigate density fluctuations near the Sun, where plasma turbulence evolves and dissipates to heat and accelerate solar wind plasma. Recent solar radio dedicated instruments in space (Parker and Solar Orbiter) allow us for the first time to accurately track radio bursts from the photosphere to the inner heliosphere, and to quantitatively test our radio wave propagation model.

How to cite: Krupar, V., Kruparova, O., Merka, J., and Pasanen, J.: Radio wAve Propagation In thE solaR wind (RAPIER), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4361, https://doi.org/10.5194/egusphere-egu23-4361, 2023.

As an alternative to the traditionally considered electron cyclotron maser (ECM) mechanism of exoplanetary radio emission (RE), we study plasma maser mechanism. The latter, contrary to ECM operates in dense and weakly magnetized plasmas, where electron cyclotron frequency fc is less than Langmuir frequency f_L [1]. Similar mechanism is known to contribute the generation of RE in solar corona, as well as in magnetospheres of the Solar System planets [2,3]. It is a two-step process. At first, the plasma waves are excited due to Cherenkov instability in a weakly anisotropic background plasma by a small admixture of hot electrons with a loss-cone type non-equilibrium distribution function. Then, the electromagnetic radiation at f_RE arises due to, e.g., plasma wave scattering on the background ions (Rayleigh scattering, f_RE = f_L), or nonlinear coupling of two plasma waves (Raman scattering, f_RE = 2f_L). In the first case, the maser effect at plasma frequency f_L takes place under certain conditions, leading to an exponential grow of the RE intensity with the growing energy of plasma waves. In the case of Raman scattering of two plasma waves, resulting in generation of the RE at doubled plasma frequency, the maser effect is absent, but the collisional dissipation of RE is significantly reduced at the same time. This improves the requirements regarding the brightness temperature of the RE source, to provide a detectable on Earth radiation flux. In both cases the frequency band of the exoplanetary RE is defined not by magnetic field, but by the structure of planetary plasmasphere and density distribution there.

We evaluate the efficiency of plasma mechanism of the RE generation and its detectability on Earth for the case of hot Jupiter HD189733b, for which the 3D structure of plasmasphere is simulated with the global multi-fluid self-consistent numerical model [4], taking into account the realistic stellar wind and radiation conditions. It is shown that the RE flux at doubled plasma frequency sharply increases from several mJy at 20MHz to several tens of Jy at 4 MHz. This means that the most favorable frequency range for detection of the RE from HD189733b falls into the decameter band in vicinity of the ionospheric cut-off.

1. Zaitsev, V.V., Shaposhnikov, V.E., MNRAS, 2022, 513, 4082 (DOI:10.1093/mnras/stac1140)

2. Zaitsev V. V., et al., A&A, 1986, 169, 345-354 (ISSN 0004-6361)

3. Zlotnik E. Y., et al., JGR Space Physics, 2016, 121, 5307-5318 (DOI: 10.1002/2016JA02265)

4. Rumenskikh, M. S., et al., ApJ, 2022, 927(2):238 (DOI: 10.3847/1538-4357/ac441d)

How to cite: Khodachenko, M. L., Zaitsev, V. V., Shaposhnikov, V. E., Rumenskikh, M. S., and Shaikhislamov, I. F.: Plasma mechanism of exoplanetary radio emissions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4514, https://doi.org/10.5194/egusphere-egu23-4514, 2023.

Auroral Kilometric Radiation (AKR) is a special type of nonthermal radio emission that is produced along auroral magnetic field lines at several thousand kilometers altitude above Earth's surface. Strong upward currents inside the AKR source region can lead to plasma instabilities and further to electrostatic solitary waves in the form of electron holes and ion holes. These small-scale plasma structures can modify the electron distribution function which is usually supposed to amplify the free-space wave modes, introducing various kinds of fine spectral features into the AKR emission pattern. We will discuss these fine spectral features based on observations from the Cluster Wideband Receiver (WBD). Spectral fine structure in AKR is frequently observed as fast frequency-drifting bursts of emission with time scales of milliseconds, or as features drifting more slowly over several seconds or a few minutes, like the well-known striations and banded emissions. The physical properties and parameter ranges of associated electron holes and ion holes are estimated based on statistics of observed WBD spectral patterns.

How to cite: Taubenschuss, U., Fischer, G., Pisa, D., Santolik, O., and Soucek, J.: Characteristics of spectral fine structure in Auroral Kilometric Radiation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5988, https://doi.org/10.5194/egusphere-egu23-5988, 2023.

Solar radio bursts (SRBs) are brief periods of enhanced radio emission from the Sun which contain information concerning the plasma where the emission originates; consequently, SRBs can provide critical information concerning space weather events such as coronal mass ejections (CMEs). A new network of four-element interferometers is being developed and used to monitor SRBs. These interferometers, called the Deployable Low-band Ionosphere and Transient Experiment (DLITE) arrays, operate in a 30-40 MHz band and were originally designed to probe the Earth’s ionosphere using high resolution measurements (1.024-s temporal resolution, 16.276-kHz frequency resolution). The DLITE network has recently been demonstrated to be  a powerful tool for detailed observations of SRBs at these frequencies. We have used DLITE to detect long-duration Type II and Type IV SRBs. Each DLITE array provides a higher sensitivity (e.g. >10 dB) compared to single-receiver stations using the same antenna. We demonstrate DLITE's enhanced functionality by examining SRBs associated with a CME on May 11, 2022. The high resolution SRB data that DLITE provides can complement ground-based networks like e-Callisto or space-based observations, e.g., from Wind/WAVES. Future improvements could be made to DLITE arrays by utilizing the 20-80 MHz band and millisecond time-resolution possible by the antennas. This would expand DLITE’s detection ability to shorter Type I and Type III SRBs and improve its ability to track long-duration bursts.

How to cite: Carson, G., Kooi, J., Helmboldt, J., Markowski, B., Bonanno, D., and Hicks, B.: DLITE—An inexpensive, deployable interferometer for solar radio burst observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8736, https://doi.org/10.5194/egusphere-egu23-8736, 2023.

INSPIRE-SAT 7 is a French 2U CubeSat very similar to the satellite UVSQ-SAT which was launched on 24 January 2021. The main purpose of INSPIRE-SAT 7 is the measurement of the Earth’s radiation budget at the top of the atmosphere. Its total mass is ~3.0 kg and its averaged power consumption 3 W. It will orbit at a maximum altitude of 600 km on a Sun-synchronous orbit with a descending node at ~0930 LT. The IONO experiment embarked on INSPIRE-SAT 7 is dedicated to the sounding of the Earth’s ionosphere which results from the ionization of the upper atmosphere due to UV radiations and X-rays coming from the Sun. The electron density in the ionosphere depends on the local time, the season, and the solar activity. The propagation of the radio waves is affected by the electron density and also by refraction and reflection phenomena. We consider the following goals for the IONO instrument: improving ionosphere models, in particular the IRI (International Reference Ionosphere); study of the propagation of electromagnetic waves in the ionosphere and the factors which can disturb it (e.g., thunderstorms); analysis of temporal and spatial variability at different scales; study of the coupling between ionosphere and magnetosphere, and the electrical circuit between ionosphere and lithosphere. The observations collected by IONO will be compared to those produced by a VLF-LF antenna network designed for investigating the perturbations of the ionosphere, and the wave propagation, by seismic phenomena.

How to cite: Galopeau, P., Meftah, M., Keckhut, P., Grossel, K., Boust, F., Boudjada, M., and Eichelberger, H.: Observation of the Earth’s ionosphere variability by IONO/INSPIRE-SAT 7 experiment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8808, https://doi.org/10.5194/egusphere-egu23-8808, 2023.

LOFAR low band interferometric images of type III solar radio bursts during an M class flare on 7 September 2017 show distinct sources with variations in their positions and intermittent dual source structures. We identify these as fundamental and harmonic emission, with the one or other being dominant at times. The data show that transport effects due to refraction and scattering play a significant role, both in source separation and drift of their apparent positions. We present a method of automatically separating fundamental and harmonic contributions that allows for obtaining separate lightcurves. Comparing the lightcurves of fundamental and harmonic pairs, e.g. 35 MHz and 70 MHz, enables studies of radio wave propagation in the solar corona. Harmonic sources at the lowest observable frequencies are relevant for the transition into the solar wind, and for joint observing campaigns with Parker Solar Probe and Solar Orbiter that are currently investigating the inner heliosphere.

How to cite: Vocks, C., Zucca, P., Bisi, M., Dabrowski, B., Morosan, D., Gallagher, P., Krankowski, A., Magdalenic, J., Mann, G., Marque, C., Rothkaehl, H., and Matyjasiak, B.: Separating fundamental and harmonic sources in LOFAR solar type III radio burst images, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12283, https://doi.org/10.5194/egusphere-egu23-12283, 2023.

Large-scale solar coronal structures may have very different signatures in low-frequency metric-decametric interferometric images than their optical/EUV counterparts, or even at higher frequencies. Notable examples are coronal holes and streamers. This may be due to scattering effects of the thermal emission in the corona, or to unexpected mechanisms contributing to the overall emission at these frequencies, such as gyrosynchrotron emission. In this work, we explore the effects of frequency and emission mechanisms (thermal and gyrosynchrotron) on large-scale coronal structures, comparing data with synthetic observations based on global magnetohydrodynamic modeling and forward modeling. We analyze observations by the LOw Frequency ARray (LOFAR) and Murchison Widefield Array (MWA) radio telescopes in a frequency range between 20-250 MHz. We address the unanswered question of why coronal holes often appear bright in the lowest frequencies observable on the ground, and whether this changes with the observer’s viewpoint. We attempt to segment and classify large-scale coronal structures based on their multiwavelength appearance and emission mechanism.

How to cite: Kozarev, K., Zucca, P., Zhang, P., Stepanyuk, O., and Nedal, M.: Exploring Coronal Structures in Metric-Decametric Radio Imaging, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13512, https://doi.org/10.5194/egusphere-egu23-13512, 2023.

Using magnetic field data collected by Mars Atmosphere and Volatile EvolutioN (MAVEN), we investigated the external magnetic field distribution over low crustal field regions in the Martian ionosphere. Both draping and looping magnetic field are observed in the Martian dayside and nightside ionosphere at attitude range 150-600 altitude. Draping magnetic field is formed by the draped interplanetary magnetic field around the ionosphere obstacle, which is formed by the well-known induced magnetosphere current system. Looping magnetic field, observed in both ionosphere and magnetosphere, indicates a new current system coupling the ionosphere and magnetosphere. This new current system, different with the induced magnetosphere current system, has sunward component in the magnetosphere, and tailward component in the low altitude ionosphere. This current system is validated by both MAVEN observation and a global multi-fluid magnetohydrodynamic (MHD) simulation, which is most likely a universal phenomenon for a non-magnetized planetary with ionospheres interacted with high-speed solar wind.

How to cite: Gao, J., Rong, Z., Wei, Y., and Lu, H.: A new magnetosphere-ionosphere current system on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9, https://doi.org/10.5194/egusphere-egu23-9, 2023.

We apply a recently presented method to estimate ion escape to Mars. The method combines in-situ observations and a hybrid plasma model (ions as particles, electrons as a fluid). Observed upstream solar wind conditions from the Mars Atmosphere and Volatile Evolution (MAVEN)  are used as input to the model.  We then vary ionospheric ion production until the solution fits the observed bow shock location.  With this method, we investigate how upstream conditions, including solar EUV, solar wind dynamic pressure, Interplanetary Magnetic Field (IMF) strength and cone angle, affect the heavy ions loss. The results indicate that the heavy ions escape rate is higher in high EUV and the tail flux is sensitive to EUV variety while the plume is not. The ion escape rate increases as solar wind dynamic pressure increases. 

How to cite: Zhang, Q., Holmström, M., Wang, X., and Nilsson, H.: The influence of upstream conditions on heavy ion escape at Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-490, https://doi.org/10.5194/egusphere-egu23-490, 2023.

We present two new methods to study the electric fields and their effect on ions and electrons in a cometary environment. One method is to look at the energy spectra of cometary ions, ions that are produced by ionisation of the gas emanating from the comet nucleus. The new production of such ions falls off with distance r to the nucleus proportionally to the fall-off of the parent neutral gas, as 1/r². For ions having been significantly accelerated, the energy of observed ions shows the electric potential difference between the point of ionisation and the observation point. When such ionisation occurs in a homogeneous electric field, the ion flux as function of energy is predicted to show a simple power law relation, the flux falling off as 1/E². This is indeed sometimes seen. We also discuss the possibility to interpret ion energy spectra in terms of somewhat inhomogeneous electric fields.

To this we can now add a new method where by comparing the speed of solar wind H⁺ and He²⁺ after interaction with the comet environment we can estimate the electric potential of the observation point relative to the upstream solar wind. Combining these methods opens up a whole new possibility to study in detail the electric fields acting on small scales when two plasma populations interact. Our study is specific to the cometary environment we are looking at, but the physical interactions we study are universal.

How to cite: Nilsson, H.: Electric fields in a small scale comet magnetosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2582, https://doi.org/10.5194/egusphere-egu23-2582, 2023.

Venus lacks a significant intrinsic magnetic field, and thus, its atmosphere and ionosphere interact directly with the solar wind flow and magnetic field from the Sun. Interplanetary magnetic fields (IMF) can penetrate into the ionosphere when the upstream solar wind dynamic pressure is stronger than the ionospheric plasma pressure. Magnetic topology can be inferred at Venus if it is defined as the magnetic connectivity to the collisional atmosphere/ionosphere, rather than connectivity to the planet’s surface. Magnetic topology can be inferred from the pitch angle and energy distribution of superthermal (> ~1 eV) electrons. More specifically, the presence of loss cones in electron pitch angle distributions infers connectivity to the nightside collisional atmosphere and the presence of ionospheric photoelectrons (identified from electron energy distributions) indicates connectivity to the dayside collisional ionosphere. We design automated procedures to determine magnetic topology with electron and magnetic field measurements by the Venus Express spacecraft over its entire mission (2006-2014). This allows us to provide the first statistical mapping of magnetic topology at Venus. We also examine how the upstream drivers affect the low-altitude magnetic topology, revealing different magnetized states of the Venus ionosphere. We find that open and closed (a surprising topology not expected at Venus) fields cluster around the terminator and draped fields dominate other regions. Our results also reveal that there is more dayside magnetic connectivity in the -E (solar wind motional electric field) hemisphere than the +E hemisphere, and during solar maximum. During solar minimum, however, there is more nightside magnetic connectivity. Last but not the least, to understand the true nature of these magnetic topologies and broadly speaking the planet-solar wind interaction, we need to think about possible ways to measure the deeply penetrated magnetic fields at Venus and Mars.

How to cite: Xu, S., Frahm, R., Ma, Y., Mitchell, D., Luhmann, J., and Persson, M.: Statistical Mapping of Magnetic Topology at Venus, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2958, https://doi.org/10.5194/egusphere-egu23-2958, 2023.

Since September 2014, NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has been measuring the in-situ ionospheric constituents of Mars. Recently, MAVEN detected the presence of large-scale plasma depletions (at least ten-fold) within the Martian ionosphere, also known as Plasma Depletion Events (PDEs). Geometrically, the Martian PDEs appear to be bubble-like plasma structures. Although the origin and formation of PDEs are not entirely understood, they are known to occur primarily on the nightside and in regions with stronger crustal magnetic fields.

In this study, we analyze the variation of magnetic field magnitude and direction and electric field power (2–100 Hz) associated with PDEs. We show that, in most cases, the magnetic fields do not considerably change within the plasma-depleted region. Conversely, the low-frequency electric field wave power is enhanced by up to two orders of magnitude at the peak depletion. Both ions and electrons within PDEs are highly magnetized. We present possible formation mechanisms of PDEs supported by recent findings.

How to cite: Basuvaraj, P., Němec, F., Regoli, L., Fowler, C., Němeček, Z., and Šafránková, J.: Ionospheric Plasma Depletions at Mars: MAVEN Observations of In-situ Plasma and Wave properties, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3122, https://doi.org/10.5194/egusphere-egu23-3122, 2023.

On June 23^rd 2022, BepiColombo performed its second gravity assist maneuver (MFB2) at Mercury. Just like the first encounter with Mercury that took place on October 1^st 2021, the spacecraft approached the planet from dusk-nightside to dawn-dayside down to an extremely close distance (within about 200 km altitude from the planet surface). Even though BepiColombo is in a so-called “stacked configuration” during cruise, meaning that the instruments cannot be fully operated yet, these instruments can still make interesting observations. Particularly, despite their limited field-of-view, the particle sensors allow us to get a hint on the ion composition and dynamics very close to the planet well before the forthcoming orbit insertion around Mercury in December 2025. In this study, we present observations of the Mass Spectrum Analyzer (MSA) at Mercury during MFB2. MSA is part of the low energy sensors of the Mercury Plasma Particle Experiment (MPPE) consortium (PI: Y. Saito), which is a comprehensive instrumental suite for plasma, high-energy particle and energetic neutral atom measurements (Saito et al., 2021) onboard the Mercury Magnetospheric Orbiter (Mio). MSA is a “reflectron” time-of-flight spectrometer that provides information on the plasma composition and the three-dimensional distribution functions of ions with energies up to ~ 38 keV/q and masses up to ~ 60 amu (Delcourt et al., 2016). In this study, we show that both H⁺ and He²⁺ ions in the 1-10 keV range are present throughout the innermost magnetosphere near closest approach. In addition, during this MFB2 sequence, MSA observations provide evidences of He⁺ ions with energies of several hundreds of eVs. These ions likely originate from the planet exosphere and are rapidly circulated within the magnetosphere. During the outbound sequence of MFB2, MSA measurements also reveal copious amounts of keV protons of solar wind origin that propagate upstream after being reflected from the bow shock.

How to cite: Delcourt, D., Hadid, L., Saito, Y., Fränz, M., Yokota, S., Fiethe, B., Verdeil, C., Katra, B., Leblanc, F., Fischer, H., Harada, Y., Fontaine, D., Krupp, N., Michalik, H., Illiano, J.-M., Berthelier, J.-J., Krüger, H., Murakami, G., and Matsuda, S.: BepiColombo second Mercury flyby :  Ion composition measurements from the Mass Spectrum Analyzer (MSA), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3369, https://doi.org/10.5194/egusphere-egu23-3369, 2023.

Ions originating from the upper atmosphere of Mars may be picked up by the impinging solar wind and interplanetary magnetic field (IMF), which forms an energetic ion plume from the dayside of the planet as a key feature of the Martian induced magnetosphere and an important ion escape channel. Consisting of mostly ions in the beginning phase of the pickup process, the orientation and morphology of the plume are largely controlled by upstream IMF conditions.

Using data from the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, we will perform a thorough investigation of the pickup ion plume under different upstream IMF conditions. Previous statistical ion flux maps by Dong et al. [2015; 2017] from MAVEN data show the plume as a more spatially spread-out feature than that in many simulation models [e.g. Jarvinen et al. 2016 and others], which is possibly due the effects of highly variable IMF conditions for the data used in those maps. We will investigate how the plume appears with selected data under quasi-steady IMF conditions. Furthermore, we will compare the plume under strong and weak IMF conditions, as well as the conditions with IMF approximately perpendicular or parallel to the solar wind direction. The morphology of the plume and characteristics of escaping pickup ions under different IMF conditions will be discussed and compared with available model results to better understand how IMF affects the formation of the plume and ion escape through this channel.

How to cite: Dong, Y., Brain, D., Ramstad, R., Fang, X., Ma, Y., McFadden, J., Halekas, J., Espley, J., and Curry, S.: Mars pickup ion plume under different IMF conditions from MAVEN observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3699, https://doi.org/10.5194/egusphere-egu23-3699, 2023.

The Mars Ion and Neutral Particle Analyzer (MINPA), one of the three scientific payloads onboard the Tianwen-1 orbiter, was designed to measure ions and energetic neutral atoms (ENAs) at Mars. From November 2021, MINPA started to collect scientific data around Mars. Here, we present MINPA's first results of the solar-wind ENAs, which are produced through the charge exchange process between the solar wind hydrogen ions and the Martian neutral exosphere. We perform a comprehensive comparison between the inflight ENA data and ground calibration results to understand the energy and angular distributions of the solar-wind ENA signals. The possible contamination of these observations by ions and solar extreme ultraviolet (EUV) is evaluated by comparing the ENA measurements with the ion data. We will present several cases of the solar wind ENA observations, and their intensities are estimated to be 10^5~10^6 cm^-2 sr^-1 s^-1, which is in good agreement with previous in situ measurements and predictions using models.

How to cite: Ma, J., Li, W., Kong, L., Zhang, Y., Wurz, P., Galli, A., Tang, B., Xie, L., Wang, L., Qiao, F., Li, L., and Wang, C.: Solar Wind Energetic Neutral Atom Observation at Mars by MINPA Onboard the Tianwen-1 Orbiter, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5058, https://doi.org/10.5194/egusphere-egu23-5058, 2023.

Hot flow anomalies (HFAs) are not only a terrestrial, but also a solar-system-wide phenomenon that could cause strong perturbations of the planetary magnetosphere and ionosphere. Based on the observations of Mars Atmosphere and Volatile EvolutioN (MAVEN) upstream of the Martian bow shock from 2014 to 2020, we have investigated the statistical properties of HFAs around Mars in this study. Our observation results show that HFAs can distribute in a wide region from the dayside to the terminator region of Mars. On average, these HFAs can last 63 seconds and have a thickness of 28 local proton gyroradii. They are more prevalent when the ambient solar wind is denser and faster. HFAs occur most preferentially for IMF magnitude from 1-4 nT. Most of HFAs around Mars are formed during the interaction between tangential discontinues and the bow shock. Heavy ions originating from Mars do not appear to affect the formation of HFAs. Martian HFAs can lead to tens of times variations of solar wind dynamic pressure only in tens of seconds, which could strongly influence the heights of Martian ionopause and induced magnetosphere boundary.

How to cite: Wu, M.: Statistical Properties of Hot Flow Anomalies around Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5405, https://doi.org/10.5194/egusphere-egu23-5405, 2023.

We report on observations made by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft at Mars, in the region of the ion plume. We observe that in some cases, when the number density of oxygen ions is comparable to the density of the solar wind protons interaction between both plasmas leads to formation of mini induced magnetospheres (iMagnetospheres)  possessing all typical features of induced magnetospheres  observed at Mars or Venus: a pileup of the magnetic field at the ‘head’ of the ion cloud, magnetospheric cavity, partially void of solar wind protons, draping of the interplanetary magnetic field around the mini obstacle, formation of a magnetic tail with a current sheet, in which protons are accelerated by the magnetic field tensions. These new observations may shed a light on the mechanism of formation of induced magnetospheres.

How to cite: Dubinin, E., Fraenz, M., Paetzold, M., Tellmann, S., DiBraccio, G., and McFadden, J.: The mini induced magnetospheres at Mars., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6347, https://doi.org/10.5194/egusphere-egu23-6347, 2023.

With the upcoming Comet Interceptor mission aiming for a flyby of an hitherto unknown long-period comet, we investigate the expected scale size of the plasma environment to be encountered during this mission. As the target comet is not known, and may not be known before the launch of Comet Interceptor in 2029, we do not know the expected outgassing rate from the nucleus. Therefore, we have no knowledge of the expected scale size of the plasma environment, which can vary by orders of magnitude. Taking the bow shock size as a characteristic size of the plasma environment, we are interested in knowing how this grows with increasing outgassing rate. Previous cometary flyby missions have generated a small statistical dataset of outgassing rates vs. bow shock distances, while computer simulations of the solar wind interaction with various comets have yielded additional datapoints of this. We combine the measured values with a large fraction of these simulations to build up a dataset that spans over four orders of magnitude in both outgassing rate and bow shock distance. The bow shock distances are normalized to the solar wind conditions (400 km/s, 5 cm-3) and ionisation rate (7e-7 s-1) at 1 AU, and also to a flow velocity of 1 km/s of the outgassing neutrals. We then compare this dataset with the gas-dynamic model of Biermann et al., (1967) which was later expanded by Koenders et al., (2013) and find a good model-data agreement. Furthermore, assuming that the bow shock takes the shape of a conic section (as has been found empirically to be the case for most planetary bow shocks) we provide an outgassing rate-dependent bow shock model. This might be useful when planning the operation time-line of Comet Interceptor, or for any other future cometary flyby mission.

How to cite: Edberg, N. J. T., Eriksson, A. I., Nilsson, H., Gunell, H., Goetz, C., Richter, I., Henri, P., and de Keyser, J.: Scale size of cometary bow shocks, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6449, https://doi.org/10.5194/egusphere-egu23-6449, 2023.

The interaction between Mars' crustal magnetic fields and the solar wind produces a variety of magnetic topologies whose characteristics depend upon the plasma regions that the magnetic field is embedded in. We utilize in-situ Mars Atmosphere And Volatile EvolutioN (MAVEN) measurements to identify localized ionospheric structures, observed as the spacecraft flies through this patchwork of different magnetic topologies. Events are characterized by sharp ‘drop outs’ in magnetic field strength that we term ‘magnetic depletions’. The plasma pressure dominates within magnetic depletions, while the magnetic pressure typically dominates outside of them. Abrupt changes in magnetic topology are coincident with the depletion boundaries. A preliminary statistical study spanning 3 months shows that events occur on ∼4% of MAVEN orbits, between altitudes of 170–360 km. Ionospheric electrons are collisionless and thus magnetized at these altitudes, and combined with the fact that magnetic diffusion timescales range from minutes to an hour, these characteristics suggest that such structures can be observed sporadically by MAVEN on its ∼4.5 hour orbit before being smeared out by magnetic diffusion. At lower altitudes high collision rates lead to diffusion timescales of seconds, while at higher altitudes electromagnetic waves, instabilities and other transport processes driven by the Mars-solar wind interaction can distort the magnetic field, making magnetic depletion events difficult to identify. Magnetic depletions highlight the ability of magnetic topology to drive localized ionospheric structure at Mars, a result that stems from the unique interaction between the solar wind, Mars' crustal magnetic fields, and it's ionosphere.

How to cite: Fowler, C., Ortiz, Z., Xu, S., Mitchell, D., Hanley, K., Espley, J., Andersson, L., McFadden, J., Luhmann, J., and Curry, S.: The influence of magnetic topology on ionospheric structure at Mars: Observations of localized “magnetic depletions”, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6512, https://doi.org/10.5194/egusphere-egu23-6512, 2023.

On August 10, 2021, the Mercury-bound BepiColombo spacecraft flew for the second time by Venus for a Gravity-Assist Maneuver. During this second flyby of Venus, a limited number of instruments were turned on, allowing unique observations of the planet and its environment. Among these instruments, the Mass Spectrum Analyzer (MSA) that is part of the particle analyzer consortium onboard the magnetospheric orbiter (Mio) was able to acquire its first plasma composition measurements in space. As a matter of fact, during a limited time interval upon approach of the planet, substantial ion populations were recorded by MSA, with characteristic energies ranging from about 20 eV up to a few hundreds of eVs. Comparison of the measured Time-Of-Flight spectra with calibration data reveals that these populations are of planetary origin, containing both Oxygen and Carbon ions. The Oxygen observations are to some extent consistent with previous in situ measurements from mass spectrometers onboard Venus Express and Pioneer Venus Orbiter. On the other hand, the MSA data provide the first ever in situ evidences of Carbon ions in the near-Venus environment at about 6 planetary radii. We show that the abundance of C+ amounts to about ~30% of that of O+. Furthermore, Changes in the orientation of the magnetic field suggest that these planetary ions are located in the distant magnetosheath flank in the immediate vicinity of the bow-shock region.

How to cite: Hadid, L. and the BepiColombo - MSA team (and members from MIA, MEA and MPO-MAG teams): Evidence of planetary Oxygen and Carbon ions in the outer flank of Venusmagnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7071, https://doi.org/10.5194/egusphere-egu23-7071, 2023.

The dynamics of induced magnetospheres raise several unsolved questions. Among the most pressing is the interaction between the solar wind and induced magnetospheres, and the corresponding changes in magnetospheric structure and variation in heating processes. Furthermore, the reactions of an induced magnetosphere to solar eruptive events such as interplanetary coronal mass ejections, corotating interaction regions and solar flares are not well understood. The Magnetospheric Venus Space Explorers (MVSE) mission is designed to fill this gap by studying how the Sun drives the dynamics of the induced Venusian magnetosphere. Venus is an ideal laboratory for this due to its proximity to the Sun, similarity to Earth, and its accessibility. Investigating the induced Venusian magnetosphere enables direct comparisons with Earth’s active magnetosphere and other induced ones, such as those of several other planets, moons and comets. This complements former missions like Venus Express (VEX) and Pioneer Venus Orbiter (PVO) by filling data and knowledge gaps, hence improving magnetospheric modeling.

Figure 1: Orbits of the three scientific spacecraft and transfer/communication spacecraft around Venus facilitating simultaneous measurements in solar wind, bow shock and magnetotail

Three identical spin-stabilised scientific spacecraft equipped with in-situ plasma instrumentation are deployed in resonant orbits around Venus by a transfer stage, which then further operates as a communication relay station. With a phase difference of 180° relative to each other, two scientific spacecraft orbit Venus circularly with a 20 h period (r = 6 Venusian radii R_V). The third spacecraft is in a resonant inner elliptical orbit with a 10 h period (pericythe = 1.3 R_V; apocythe = 6 R_V) . This configuration enables simultaneous measurements in three regions of interest (ROIs): i) up and ii) downstream the bow shock, as well as iii) in the magnetotail. In these ROIs, the magnetic field, the electric field and the ion-electron distribution functions are measured. To observe at least 10 coronal mass ejection events, a mission duration of three years around the solar maximum is planned.

Figure 2: Spacecraft stack consisting of one tansfer/communications vehicle and three scientific spacecraft

The concept of the MVSE mission was developed during ESA’s Alpbach Summer School 2022. It has been refined by adapting the concurrent engineering method during the Post Alpbach Summer School Event 2022. A total of 32 students from both engineering and science backgrounds worked on the mission with appreciated advice from experts of ESA and academia.

How to cite: Maraqten, N. and Kutnohorsky, V. and the MVSE Mission Team: MVSE Mission Phase A/0 Study: A Proposal for Understanding the Dynamics of Induced Magnetospheres, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8206, https://doi.org/10.5194/egusphere-egu23-8206, 2023.

Comet Interceptor is the ESA F1 space mission aiming to explore a comet very likely entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star, scheduled for launch in 2029 together with the ESA L-class Ariel spacecraft. Following the mission adoption in June 2022, the spacecraft and scientific payload development have advanced to the Phase C. In our contribution we present the status of development of the Low-energy electron spectrometer (LEES) that is a part of the Dust-Fields-Plasma multi-instrument suite deployed at the main spacecraft A (DFP-A).

The DFP-A/LEES sensor will determine the thermal and suprathermal electron densities, temperatures, and the velocity distribution functions of the local plasma environment of both the solar wind and coma. It will also measure the local properties of negatively charged ions and dust, and detect photoelectrons resulting from neutral-plasma interactions in order to infer the magnetic connectivity between the cometary environment and the spacecraft. The LEES measurements are needed to understand the ionization sources of the cometary neutral gas as well as to infer the plasma boundaries of the induced magnetosphere of the comet. The electron spectrometer is a further miniaturized version of the top-hat analyser inherited from the Stereo, Maven and BepiColombo missions. We present the overall design, simulation of the spacecraft electromagnetic and particle environment influence to the LEES measurements and the intermediate results of testing of the LEES components to survive a potential harsh dust environment during the comet flyby.   

How to cite: Prech, L., André, N., Lavraud, B., Verdeil, C., Fedorov, A., and Vaverka, J. and the LEES Technical and Scientific Teams: Low-energy electron spectrometer to study the far environment of a dynamically new comet as a part of the Comet Interceptor payload, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8319, https://doi.org/10.5194/egusphere-egu23-8319, 2023.

The ion spectrometer ICA onboard the Rosetta mission has provided us with detailed measurements of the plasma environment around comet 67P/Churyumov-Gerasimenko. The distribution of cometary ions is an important indicator for the cometary plasma environment and its interaction with the solar wind. The cometary ion production at a comet decreases with increasing radial distance from the comet. The fluxes of observed ions are therefore also expected to fall off proportional to their point of origin relative to the comet. Due to electric fields, ions that are born further away are observed at higher energies at the spacecraft. The exact relation between the flux and the observed energy depends on the density distribution of cometary ions and the electric field around the comet.
We derive the bulk flow properties of the cometary pickup ion population with a fitting procedure. In our study, cometary pickup ions are all heavy ions with an energy above 40 eV as observed by ICA. The particle drift speed of the bulk flow can be used to estimate the average local electric field. This gives us a 3D estimate for the electric field close to the comet nucleus. Using this E-field estimate, we can back-trace the observed particles to determine an approximate location of where they were born. This ionisation point is further away for particles with higher energies. The relation between the flux of the observed ions and their origin provides us with information about the inhomogeneity of the cometary plasma environment between the observation point (30 km from the nucleus) and the ionisation point of the particle (hundreds of km away from the nucleus). 
We will present results of the ion distribution of cometary pickup ions above 40eV on a selected day (April 19th, 2016) of the Rosetta mission, along with the derived electric field estimate close to the nucleus. We will also show the results and implications of the particle trajectory backtracing.

How to cite: Moeslinger, A., Nilsson, H., Stenberg Wieser, G., and Williamson, H.: E-field at a low-activity comet derived from cometary ion velocity distributions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8912, https://doi.org/10.5194/egusphere-egu23-8912, 2023.

We present a numerical work in which the interaction between a comet and the solar wind is studied in 2D in the plane perpendicular to the solar wind mean field direction. Our simulations are conducted with the hybrid Particle-in-Cell (PIC) code Menura that allows for the injection of a turbulent solar wind [1].

First, we consider the case of laminar solar wind and we present a study on the equivalent Mach number of the two-ion-species (cometary and solar wind) plasma surrounding the comet. We develop an expression for the Mach number having suitable limits in the two asymptotic cases of infinite cometary and solar wind ion density; our expression is derived by extending previous studies on bi-ion plasma models [2]. Through numerical simulations in which the cometary activity is varied, we show how our Mach number is able to unambiguously describe  the existence and location of the cometary shock.

Second, we compare two runs, one with a laminar and one with a turbulent solar wind in the case of moderate cometary activity. We divide the simulation domain into the regions upstream and downstream the cometary shock. We analyze how plasma turbulence properties are affected by the passage through the shock in the case of a turbulent solar wind. Then, we divide the downstream region into three different regions identified by different solar wind-to-cometary ion density ratios. We study the downstream turbulence properties in the case of laminar and turbulent impinging solar wind and how they vary in those regions.

[1] Behar, E., Fatemi, S., Henri, P., & Holmström, M. (2022, May). Menura: a code for simulating the interaction between a turbulent solar wind and solar system bodies. In Annales Geophysicae (Vol. 40, No. 3, pp. 281-297). Copernicus GmbH.

[2] Dubinin, E. M., Sauer, K., McKenzie, J. F., & Chanteur, G. (2002). Nonlinear waves and solitons propagating perpendicular to the magnetic field in bi-ion plasma with finite plasma pressure. Nonlinear Processes in Geophysics, 9(2), 87-99.

How to cite: Pucci, F., Behar, E., Henri, P., Simon Wedlund, C., and Ballerini, G.: Plasma turbulence within cometary plasma environments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9003, https://doi.org/10.5194/egusphere-egu23-9003, 2023.

The study of the structure and dynamics of Mercury’s magnetosphere is still an open research topic in space physics. Upon other mission objectives, the on-going BepiColombo mission will study the plasma environment around Mercury with multiple field and particle instruments. One of them is the Planetary Ion Camera (PICAM). It is an ion spectrometer designed to measure low-energy pick-up heavy ions (e.g. sodium). Due to ejection mechanisms and the solar wind influence, these particles are emitted from the surface of Mercury. The resulting electric currents, like perpendicular and field-aligned currents need to be studied to understand the global magnetospheric current structure as well as its variability due to the solar wind conditions.

In this study, numerical simulations with a global 3D hybrid model are used to investigate and forecast the typical ion profile with energies up to 5 keV during the BepiColombo flyby trajectories in the years 2021-2025. Magnetotail reconnection causes the acceleration of particles towards the planet. The resulting field-aligned current is studied to about 3 R_M in tailward direction. The simulations are conducted with the AIKEF (Adaptive Ion Kinetic Electron Fluid) model. The kinetic treatments of the ions will enable to directly compare magnetospheric particle species model results with PICAM observations.

How to cite: Teubenbacher, D., Narita, Y., Laky, G., Varsani, A., Schmid, D., Motschmann, U., Töpfer, S., Exner, W., Bourdin, P., and Comişel, H.: Expectations of the Ion-Profile in Mercury’s Magnetosphere during BepiColombo's Flybys 2021-2025, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9224, https://doi.org/10.5194/egusphere-egu23-9224, 2023.

Accelerated electron populations observed in the nightside ionosphere of Mars are investigated using measurements obtained by MAVEN’s Solar Wind Electron Analyzer. The measurements are of particular interest as they extend to altitudes as low as 130 km and to regions characterized by strong crustal magnetic fields, allowing us to investigate the evolution of the electron distributions in the complex crustal fields and determine the rate by which the accelerated populations precipitate into the Martian upper atmosphere.

The majority of the observed accelerated electrons are trapped in the crustal fields, bouncing between mirror points, presumably drifting across magnetic field lines, but without instantaneous access to the collisional atmosphere. The average energy flux of these electrons is significant when compared to that of the much more common ‘unaccelerated’ sheath electrons. Considering that the Martian crustal magnetic fields do not provide a closed path for drifting particles, the trapped electrons are bound to exit the crustal fields and either precipitate into the atmosphere or escape. Currently, we estimate that, despite their low detection rate (< 1%), the accelerated electrons account for about 10% of the total energy that is deposited into the nightside ionosphere by electron precipitation. Further, the peak energy of the accelerated electrons is generally found in the range of tens to hundreds of eV, consistent with the energy range previously suggested for the generation of discrete aurora emissions observed on Mars.

How to cite: Akbari, H., Fowler, C., and Andersson, L.: Precipitation of accelerated electrons at Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9425, https://doi.org/10.5194/egusphere-egu23-9425, 2023.

The thermal electron temperature, Te, is an important quantity in planetary ionospheres because many photochemical reaction rates depend on it. Te thus plays a role in driving ion composition, structure and dynamics. In addition, enhancements in Te with altitude have been shown to drive ambi-polar electric fields that can energize cold planetary ions and lead to ion escape to space.

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission acquires Te profiles on each orbit and as a result, a comprehensive data set exists that spans the full range of Mars local times, latitudes and solar zenith angles, allowing us to determine which physical processes control the Te profile shapes and temperature values. We focus on the “transition region,” where Te values can rapidly increase from small values (<500 K) at lower altitudes, to larger values (>1000 K), over a relatively narrow altitude range. The suite of plasma instruments carried by MAVEN allows us to investigate the role of, for example, electron-neutral collisions, ion temperature, wave heating, etc. This study focuses on the effect of electron-neutral collisions on the location and width of the Te transition region. We utilize observations of the neutral atmosphere made by MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS) instrument to calculate electron–neutral collision frequencies, which are compared to measured Te profiles. The calculated collision frequencies provide insight on when collisional processes dominate (over transport and electromagnetic waves, for example), and allow us to identify trends between driving processes and the shape and location of the Te transition region. Understanding the physical processes that control the form of Te profiles will inform us of the mechanisms key to structuring the current day Mars ionosphere. Such understanding will also provide key insight needed for studies of ionospheric escape to space and long-term evolution of the Martian atmosphere. 

How to cite: Turner, A., Fowler, C., and Andersson, L.: Determining the Relation Between Electron-Neutral Collisions and Thermal Electron Temperature Profiles in the Mars Ionosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9448, https://doi.org/10.5194/egusphere-egu23-9448, 2023.

Around 17 December 2021, the Solar Orbiter spacecraft was predicted to have had its closest approach to comet C/2021 A1 (Leonard) with a minimum streamline distance < 0.01 AU. This encounter provided an unprecedented opportunity to investigate in situ comet Leonard's interaction with the solar wind and the composition of pick-up ions produced by ionization and dissociation of outgassed neutrals from its coma. It was a long-period comet originating from the Oort Cloud with a nucleus about 1 km in diameter, with ground-based telescope observations after its perihelion pass (at ~0.62 AU on 3 January 2022) indicating that it had subsequently disintegrated. Prior to perihelion, outbursts had been reported as well as variations in brightness, which had resulted in speculation about an impending disintegration. However, the dimming in November 2021, before the Solar Orbiter encounter, was argued to be due to a transition from outgassing dominated by carbon dioxide to water. Comet Leonard was the brightest comet of the year and noted for its spectacular ion tail with complex structures, including knots and streamers. Preliminary analysis of in situ Solar Orbiter observations have revealed tell-tale signatures of a cometary encounter around the time of predicted closest approach, such as evidence for magnetic field line draping. However, the clearest evidence has come from Solar Wind Analyzer-Heavy Ion Sensor (SWA-HIS) observations of singly-charged oxygen ions, which are typically not of solar origin and are usually produced when the solar wind interacts with a comet or other Solar System body. In this presentation we use SWA-HIS and EDP-STEP data to investigate aspects of the solar wind interaction and composition of cometary pick-up ions from this active, long-period comet shortly before its disintegration.

How to cite: Stubbs, T., Galvin, A., Livi, S., Delano, K., Ellis, L., Kistler, L., Dewey, R., Raines, J., Lepri, S., Lario, D., Jones, G., Grant, S., Wurz, P., Kucharek, H., Owen, C., Fedorov, A., Louarn, P., Matteini, L., Berger, L., and Wimmer-Schweingruber, R. and the The Heavy Ion Sensor (HIS) Science Team: Solar Orbiter Observations of Ion Species during the Encounter with the Tail of Comet Leonard, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9550, https://doi.org/10.5194/egusphere-egu23-9550, 2023.

Mercury possesses a miniature but dynamic magnetosphere driven primarily by the solar wind through magnetic reconnection. A prominent feature of the dayside magnetopause reconnection that has been frequently observed is flux transfer events (FTEs), which are thought to be an important player in driving the global convection at Mercury. Using the BATSRUS Hall MHD model with coupled planetary interior, we have conducted a series of high-resolution global simulations to investigate the generation and characteristics of FTEs under different solar wind Alfvénic Mach numbers (M_A) and IMF orientations. In all simulations driven by steady upstream conditions, FTEs are formed quasi-periodically with recurrence time ranging from 2 to 9 seconds, and their characteristics vary in time as they evolve and interact with the surrounding plasma and magnetic field. Our statistical analysis of the simulated FTEs reveals that the key properties of FTEs, including spatial size, traveling speed and core field strength, all exhibit notable dependence on the solar wind M_A and IMF orientation, and the trends identified from the simulations are generally consistent with previous MESSENGER observations. It is also found that FTEs formed in the simulations contribute a significant portion of the total open flux created at the dayside magnetopause that participates in the global circulation, suggesting that FTEs indeed play an important role in driving the Dungey cycle at Mercury.

How to cite: Jia, X. and Li, C.: Global Hall MHD simulations of Mercury's magnetosphere: Formation and properties of flux transfer events (FTEs) under different solar wind conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10183, https://doi.org/10.5194/egusphere-egu23-10183, 2023.

Mercury possesses a weak planetary dipole moment and is subject to a strong solar wind inflow. Thus, a small magnetosphere is formed. On the nightside, a neutral current sheet elongates the magnetic field lines to form a magnetotail. From hybrid simulations it is known that this current sheet reacts to changes in the interplanetary magnetic field (IMF). In order to understand the magnetospheric reaction to changes in the solar wind, it is essential to further assess the neutral current sheet movements. The strongly radial IMF at Mercury facilitates magnetopause reconnection in high latitudes which decreases the magnetic pressure in one of the magnetospheric lobes depending on the radial IMF polarity. This produces a northward (or southward) shift of the neutral sheet. Here, we present statistical results from in-situ MESSENGER magnetic field data analysis on the IMF direction as well as the neutral sheet displacement. MESSENGER was a single probe in orbit around Mercury and, as such, it was blind to the solar wind state after having entered the bow shock. Thus, we need to estimate the current IMF radial polarity for the time frame with the probe located inside the magnetosphere. For this, we evaluate different interpolation methods with an adapted bootstrap analysis method on data taken within the upstream solar wind at Mercury. Eventually, the outcome of the statistical analysis on the neutral sheet displacement is compared to the results from hybrid simulations done in the past.

How to cite: Heyner, D., Pump, K., Hercik, D., Exner, W., Narita, Y., Plaschke, F., Schmid, D., Slavin, J., and Volwerk, M.: Neutral Current Sheet Displacement in Reaction to the Radial Interplanetary Magnetic Field at Mercury: Statistical Results from MESSENGER Data., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11546, https://doi.org/10.5194/egusphere-egu23-11546, 2023.

While waiting for further insights from the upcoming data from the BepiColombo mission, this work presents some results from full-scale 3D hybrid (ions kinetic and electrons fluid) computer simulations of the near-Mercury environment under different interplanetary conditions. During its orbit Mercury passes from an high density high magnetic field intensity region (Perihelion) to a low density low magnetic field intensity region (Aphelion). Such environment change drastically influences the response of its magnetic environment, including the stand-off distance of both Bow-Shock and Magnetopause. Being these latter not distant from each other nor from the Hermean exosphere, such a dynamics may lead to important interactions between the planetary and interplanetary environments, as well as lead to unpredictable scenarios whenever the interplanetary conditions occasionally result more extreme than those average values curretly known.

Here we aim to give more insights  into the near-Mercury environments under more significant interplanetary conditions by means of full-scale 3D multi-species hybrid simulations, including the Aphelion and Perihelion conditions known to date, as well as more extreme conditions, and compare these results with currently available in-situ observations and recent similar computer simulations. 

How to cite: Cazzola, E., Fontaine, D., and Modolo, R.: On the Response of the near-Mercury Environment to Different Interplanetary Conditions from full-scale 3D Hybrid Simulations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11568, https://doi.org/10.5194/egusphere-egu23-11568, 2023.

Water was abundant on early Mars but disappeared, likely escaping into interplanetary space.

Large-scale planetary magnetic fields were long thought to shield planetary atmospheres and limit atmospheric escape, suggesting that Mars lost most of its water after its intrinsic magnetic field vanished. However, observations of atmospheric escape from Mars, Venus and Earth as well as recent numerical models question the protective effect of planetary magnetic fields on atmospheric erosion.

We use a semi-empirical model of atmospheric escape to investigate the past oxygen and hydrogen escape rate from Mars. This model uses physical considerations and a magnetic field model to extrapolate present-day observations to past solar and planetary conditions. It accounts for the variation of the planetary magnetic field and of the solar wind dynamic pressure and EUV/UV flux. Our modelling results show that for a more active Sun, atmospheric escape peaks for a weak planetary magnetization level as both unmagnetized escape processes like ion pick-up and sputtering can occur at the same time as magnetized escape processes in the polar regions. This study suggests that the water loss rate from the Martian atmosphere may have peaked when Mars was (still) magnetized rather than when it was unmagnetized.

How to cite: Maggiolo, R., Alonso Tagle, M. L., Gunell, H., De keyser, J., Cessateur, G., Lapenta, G., Pierrard, V., and Vandaele, A. C.: Investigating the past atmospheric escape rate from Mars using a semi-empirical model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12193, https://doi.org/10.5194/egusphere-egu23-12193, 2023.

Titan’s  magnetotail is formed as a result of the interaction of Saturn’s magnetospheric flow with Titan’s ionosphere. While the ionosphere is created mainly by EUV radiation and impinging magnetospheric particles on the atmosphere, the tail is more governed by plasma outflow processes, the upstream magnetospheric flow properties (density, flow velocity) and the upstream magnetic field direction. The properties of Titan’s tail has previously been studied with both numerical simulations and in-situ measurements. For instance,  the escape rate has been shown to be of the order  of order ~10²⁴ s^-1, and case studies have revealed a highly dynamic tail structure.

In this work we make an attempt to combine observations of electrons and ions in Titan’s tail for all of the Cassini flybys. We use the Langmuir probe (RPWS/LP) and the Cassini Plasma Spectrometer (CAPS) ion and electron measurements. We put a spatial constraint on the tail’s geometry  and its orientation based on the measurements of electron and ion densities. The estimation of escape rate is revisited, and different sources of variability and their impact on the tail structure are discussed. Furthermore, the link between the convectional electric field E = -v×B and the electron densities distribution is studied. The interim result is that the electron density tends to have higher densities in the hemisphere of positive upstream electric field. This is observed in the altitudes below the dynamo region, which is the chemistry-dominated region. The explanation of the observed distribution tendency is discussed.

How to cite: Kim, K., Edberg, N., Shebanits, O., Wahlund, J.-E., and Vigren, E.: Titan's tail structure: the multi-instrument study as observed by Cassini, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12605, https://doi.org/10.5194/egusphere-egu23-12605, 2023.

BepiColombo MPO and Mio spacecraft encounter the Mercury magnetosphere six times from 2021 to 2025 during the flyby maneuvers. Each flyby trajectory is unique and includes the magnetospheric regions that were not covered by MESSENGER. Mio/MGF magnetic field data were successfully retrieved during the Mercury flyby-2 in June 2022 and the data were calibrated for the scientific use. The MGF measurements show a short-time intense magnetic field depression in close proximity to the planet at local midnight, which is neither expected from the earlier observations (Mariner-10, MESSENGER) nor from the hybrid plasma simulations of the Mercury magnetosphere. Both time-dependent and time-independent scenarios are possible, including the occurrence of a transient event driven by sudden changes in the solar wind (e.g., pressure puls) or in the magnetosphere (e.g., magnetic reconnection) and the crossing of a localized current layer separating the dipolar field region from the stretched tail-like magnetic field region. While more dedicated analyses (wave analysis, variation analysis), combination with the other data (plasmas and imaging), and numerical simulations for different scenarios would improve the quality of scientific interpretation of the depression event, our study demonstrates the scientific potential of BepiColombo that it will detect various kinds of transient events and localized structures in Mercury’s magnetosphere already during the flyby maneuvers.

How to cite: Schmid, D., Fischer, D., Magnes, W., Narita, Y., Volwerk, M., Baumjohann, W., Matsuoka, A., Auster, H.-U., Richter, I., Heyner, D., Plaschke, F., and Nakamura, R.: Unexpected local magnetic depression around Mercury: BepiColombo flyby-2 discovery, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12906, https://doi.org/10.5194/egusphere-egu23-12906, 2023.

BepiColombo was launched in October 2018 and is currently en route to Mercury. Although its orbit insertion is planned for December 2025, BepiColombo will acquire new measurements during planetary flybys. During the cruise phase, the two spacecraft are docked together with Mio being protected behind the MOSIF sun shield. Thus, only partial observations of plasma distribution functions can be obtained by the Mercury Plasma Particle Experiment (MPPE) onboard Mio. However, since electrons have small Larmor radii and more isotropic distributions even in the solar wind, the two Mercury Electron Analyzer (MEA) of MPPE will provide us with new and unique measurements in the range of 5 eV to 3 keV when in solar wind mode and 3 eV to ~ 26 keV when in magnetospheric mode. We will present the interesting observations obtained by MEA onboard Mio/BepiColombo during its second Mercury flyby that happened on the 23^rd of June, 2022. In particular we will focus on the properties of the low- and high-energy electron populations observed during its crossing of Mercury’s magnetosphere.

How to cite: Aizawa, S., Andre, N., Saito, Y., Persson, M., Sauvaud, J.-A., Fedorov, A., Yokota, S., Barthe, A., Penou, E., Rojo, M., and Murakami, G.: Electron populations observed by Mercury Electron Analyzer onboard Mio/BepiColombo during its second Mercury flyby, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13257, https://doi.org/10.5194/egusphere-egu23-13257, 2023.

Inside the cometopause of comet 67P/Churyumov-Gerasimenko, where cometary ions dominate the ionosphere, is a region of great interest for studying the mass loading of the solar wind. The Rosetta Ion Composition Analyzer (ICA) observed both cometary and solar wind ions in this region during Rosetta’s two year mission orbiting comet 67P. Analysis of this data is complicated by instrumental and spacecraft effects on low energy cometary ion data, which comprises the bulk of the plasma. Recent work has been able to correct the ICA ion distributions for these effects and retrieve low energy ion Maxwellian temperatures and velocities, showing both a cold (< 1 eV) newly ionized plasma and higher energy, warmer pickup ions. Here, we present the varying cometary and solar wind ion temperatures inside the cometopause, with discussion of the causes for the changes in velocity and temperature throughout the time periods studied. In particular, pickup ion distributions vary significantly, from distributions similar to the newly ionized plasma at higher energies to one that decays exponentially with energy. Further, we calculate thermal and dynamic pressures of the cometary and solar wind ions using the retrieved temperatures and velocities, allowing us to analyze the pressure balance between the different plasma components. 

How to cite: Williamson, H., Stenberg Wieser, G., Nilsson, H., Moeslinger, A., Wieser, M., and Canu-Blot, R.: Plasma parameters inside the cometopause of comet 67P-Churyumov/Gerasimenko, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13641, https://doi.org/10.5194/egusphere-egu23-13641, 2023.

Understanding the plasma interactions between induced Venus magnetosphere and solar wind is crucial, especially at the kinetic scale (below the proton Larmor radius). This is because different kinetic-scale electric field structures that are associated with plasma instabilities such as double layers are good indicator of wave-particle energy transfer (Malaspina et al., Geophysical Research Letters, 47, 2020). Structures such as double layers, phase-space holes can emit radio waves (Goodrich and Ergun, The Astrophysical Journal, 809, 2015) or scatter electrons with energy of the order of keV (Vasko et al., Journal of Geophysical Research: Space Physics, 122, 2017). Double layers can create plasma instabilities (Newman et al., Physical Review Letters, 87, 2001), provide heating and acceleration to different particles (Ergun et al., Journal of Geophysical Research: Space Physics, 109, 2004). These structures have already been found in several parts of the earth’s magnetosphere. But due to a lack of high resolution data, observations of these processes are sparse in the magnetospheres of the other planets. The seven encounters that the Parker Solar Probe (PSP) spacecraft will make with Venus’s induced magnetosphere will provide excellent opportunities to measure these processes in this planet. The current talk describes the presence of kinetic-scale electric field structures during the 4^th encounter of PSP with Venus’s induced magnetosphere. For this purpose, high resolution electric field data from the PSP FIELDS instrument were used with alongside the FIELDS magnetometer data and data from the Solar Wind Electrons Alphas and Protons (SWEAP) instrument. From these observations, it is found that the PSP passed through Venus’s magnetosheath and tail region during this encounter.  This talk describes the possible presence of plasma double layers when PSP was at the boundary of the magnetosheath region. Phase-space holes are also identified near some of the double layers in this region.

How to cite: Sur, D. and Malaspina, D.: Observation of Possible Kinetic Structures at the Venus Magnetosphere using High Resolution Parker Solar Probe Data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14802, https://doi.org/10.5194/egusphere-egu23-14802, 2023.

An important topic in the field of space physics is the quantification of the cosmic-ray-induced effects in the atmosphere and the corresponding space weather effects. Space weather effects, specifically the exposure to radiation at aviation altitudes, represent an important threat. Here, we focus on a specific class of events due to solar energetic particles (SEPs), viz. events that can be registered at ground level: ground-level enhancements and more particularly extreme events with cosmogenic imprints,i.e. that have been registered by 14C records.

Naturally, for assessment of space weather effects during extreme SEP events, it is necessary to possess precise information on their spectra. Here we present results and application of an analysis of SEPs using neutron monitor (NM) records, that is derivation of their spectra, and application of numerical models. Using reconstructed spectra during the strongest directly recorded event, that is GLE # 5, occurred on 23 February 1956, and employing a convenient rescaling,  we assessed the space weather effect during the strongest indirectly reconstructed historical extreme SEP event, that is, 774 AD. Subseqeuntly, employing a state-of-the-art reconstruction of the magnetic field we study the worst-case scenario representing a combination of a geomagnetic excursion, that is the Laschamp excursion ca. 42 kyr ago and a 774 AD-like event. The possible implications are discussed.

How to cite: Mishev, A., Panovska, S., and Usoskin, I.: Space weather during extreme SEPs: new assessment of worst case scenario, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-185, https://doi.org/10.5194/egusphere-egu23-185, 2023.

We present a new open-source tool for magnetospheric computations, that is modelling of cosmic ray propagation in the geomagnetosphere, named "Oulu - Open-source geomagneToSphere prOpagation tool" (OTSO). A tool of this nature is required to interpret experiments and study phenomena within the cosmic ray research field.  Here, we demonstrate several applications of OTSO, namely the computation of asymptotic directions of selected cosmic ray stations, effective rigidity cut-off across the globe at various conditions within the design, and general properties, including the magnetospheric models employed. OTSO was applied to the investigation of several ground-level enhancement events after which comparison and validation of OTSO with older widely used tools such as MAGNETOCOSMICS was performed, and good agreement was achieved. The necessary background for the analysis of two notable ground-level enhancements was produced using OTSO and their spectral and angular characteristics show good agreement with prior studies and spacecraft data. This validation of OTSO's current abilities reveals its usefulness to the cosmic ray research field and its open-source nature further allows for the tool to be developed beyond its current capabilities by users to meet the needs of the research community.

How to cite: Larsen, N., Mishev, A., and Usoskin, I.: A New Open-Source Geomagnetosphere Propagation Tool (OTSO) and its Applications, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-287, https://doi.org/10.5194/egusphere-egu23-287, 2023.

Soil moisture (SM) sensors are widely used to monitor soil water dynamics and support irrigation management with the aim of achieving better yields while reducing water consumption. Unfortunately, due to the small measuring volume of point-scale sensors, their soil moisture readings are often not representative for heterogeneous agricultural fields. Therefore, in such cases, sensors with larger sensing volume are needed to address spatially variable SM. A suitable technique is the cosmic ray neutron sensor (CRNS) as it integrates SM over a large volume with a radius of ~130-210 m and a penetration depth of ~15-85 cm. The CRNS method is based on the inverse relationship between measured environmental neutron density and the presence of hydrogen pools (e.g., SM) in the instrument surroundings. However, the ability of CRNS to accurately monitor areas with complex SM heterogeneities (e.g., small irrigated fields) and the influence of detector design were not yet investigated. In this study, we used the neutron transport model URANOS to simulate the effect of SM variations on a CRNS placed in the centre of squared irrigated fields (0.5 to 8 ha dimensions). For this, SM in the irrigated field and in the surrounding was altered between 0.05 and 0.50 cm³ cm^-3 (500 simulations in total). In addition, we investigated the effect of employing high-density polyethylene (HDPE) moderators with different thickness (5 to 35 mm) as well as a 25 mm HDPE moderator with an additional gadolinium oxide thermal shielding. Results showed that, in heterogeneous SM scenarios, the 2 e-folding lengths footprint (R86) can become smaller or larger than what previous studies showed in homogeneous SM distributions. In addition, a thin HDPE moderator will result in relatively smaller R86 whereas thicker moderators and the addition of a thermal shielding will result in relatively larger R86. However, we found that a relatively small footprint is not directly related to a better monitoring of SM nearby the instrument. In fact, in all the investigated field dimensions, the 25mm HDPE moderator with gadolinium shielding showed the largest values of R86 but also the largest variations of detected neutrons with changing SM. In addition, such moderator showed the highest chances of detecting irrigation events that increase SM by 0.05 or 0.10 cm³ cm^-3 in the irrigated area. Generally, detection was uncertain only for SM variations of 0.05 cm³ cm^-3 in fields of 0.5 ha when initial SM was 0.02 cm³ cm^-3 or higher. Although the results of this study suggest the feasibility of monitoring and informing irrigation with CRNS, we found that SM variations outside the irrigated field have a considerable influence on CRNS measurements. Especially in fields of 0.5 and 1 ha dimension, it can be impossible to distinguish whether a relative change in detected neutrons is due to irrigation or to SM variations in the surroundings. These results are relevant for irrigation monitoring and the combination of neutron transport simulations and real-world installations has the potential to establish CRNS as a decision support system for irrigation management.

How to cite: Bogena, H., Brogi, C., Köhli, M., Hendricks Franssen, H.-J., Dombrowski, O., and Huisman, J. A.: Effects of heterogeneous soil moisture distributions in cosmic-ray neutron sensing - the case of irrigation monitoring, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3095, https://doi.org/10.5194/egusphere-egu23-3095, 2023.

ORCA (2.37 GV) is a suit of two neutron monitors and a muon telescope. It was installed at Juan Carlos I Antarctic Base on January 2019 being in operation since. Because the low level of the solar activity, only a few of solar events have been detected. The GLE 73 and three Forbush decreases. A new ORCA like detector (ICaRO, 11.5 GV) is being installed at 2200 m a.s.l in Izaña Atmospheric Observatory (Tenerife Island, Spain). On the other hand, CaLMa neutron monitor (6.95 GV) will be updated with a muon telescope made by eight 1 m² scintillators arranged in two layers of four scintillators at some point during the next two years. These three detector will measure muons and neutrons from cosmic ray interaction with atmosphere at three different locations allowing to study the solar activity from a new perspective

How to cite: Blanco, J. J., García Tejedor, J. I., Ayuso de Gregorio, S., García Población, Ó., López-Comazzi, A., Sanz Martín, D., Vrublevskyy, I., Gonzalvo Ballano, L., and Regadío, A.: ORCA (Observatorio de Rayos Cósmicos Antártico), current status and future perspectives, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4506, https://doi.org/10.5194/egusphere-egu23-4506, 2023.

Cosmogenic radionuclide Beryllium ⁷Be concentration is primarily determined by the solar activity level and space weather conditions. The ⁷Be is generated by cosmic ray reactions in the stratosphere and in the upper troposphere, binds to atmospheric aerosols and is transported horizontally and vertically by wind and gravity. The highest values of cosmic radiation are observed during the solar minima because, at that time the penetrability of the Earth’s and Sun magnetosphere is greatest.

The concentrations of the radionuclide ⁷Be are reliable indicators of various atmospheric processes. In our work, we try to contribute to better understanding of the dynamics of processes by associating them with long-term trends of stratospheric temperature dynamics. We investigate the coupling of concentrations of the cosmogenic radionuclide ⁷Be in the longitudinal view during the years 1986–2022 (time series of activity concentration of ⁷Be in aerosols evaluated by the corresponding activity in aerosols on a weekly basis at the National Radiation Protection Institute Monitoring Section in Prague) to space weather parameters (Kp planetary index, disturbance storm time Dst, proton density, proton flux), and stratospheric dynamics parameters (temperature, zonal component of wind, O₃). On short timescales the intensity of cosmic radiation decreases by few percent in several days. On a longer timescale the intensity of galactic cosmic rays is strongly influenced by the degree of solar activity and by variations in the geomagnetic field. This corresponds with findings that the zonal wind climatology differences were largest in the decades of 2000–2010 than between others observed decades.

How to cite: Podolská, K., Kozubek, M., Hýža, M., and Šindelářová, T.: The concentration of cosmogenic radionuclide 7Be from the perspective of space weather and long-term trends in the stratospheric temperature and wind, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6045, https://doi.org/10.5194/egusphere-egu23-6045, 2023.

Biomass estimation is important in many applications, such as carbon sequestration and precision agriculture. Developing a reliable method for biomass estimation from satellite, airborne and near-surface remote sensing sensors is an ongoing task due to the large uncertainty in current methods, which are often related to sensor limitations. Indeed, signals from optical sensors and synthetic aperture radar at high and medium frequencies suffer from saturation issues at high biomass levels. The Cosmic-Ray Neutron Sensor (CRNS) is a new non-invasive near-surface sensor used primarily to estimate soil water content (SWC), but it has also shown potential for retrieving other hydrological and environmental parameters such as biomass water equivalent and snow depth. The CRNS detects and counts the number of neutrons controlled by hydrogen atoms in the soil, air just above the ground, and vegetation. Biomass attenuates the intensity of cosmic ray neutrons, hence the ability to estimate biomass from a CRNS. Recent studies have used CRNS measurements to estimate biomass changes in crop areas and forest stands, while the use of CRNSs in orchards is limited. The objective of this study is to explore the potential of two CRNSs to estimate the biomass variation in irrigated cherry and olive tree orchards. The olive tree orchard is located in an arid region in northern Saudi Arabia (plantation density of 1667 trees/hectare) with an average tree height of 3 m and canopy diameter of 2 m. The cherry field is located in southern France (plantation density of 260 trees/hectare) with an average tree height of 3.5 m and canopy diameter of 5.5 m. Several soil moisture probes recording soil water content (SWC) at 15-min intervals at both sites were installed at different depths within the CRNS footprint. SWC measurements were used to assess the variations in the sensitivity of CRNS to soil moisture with increasing biomass. Tree parameters (height, canopy width, canopy length, leaf area index, and diameter at breast height) were measured in situ to estimate biomass using allometric equations. In addition, repetitive Light Detection and Ranging (LiDAR) scanning was performed over the cherry field to detect canopy volume changes over time. The results showed that the CRNS is sensitive to SWC variation, and this sensitivity is controlled by biomass evolution, indicating that CNRS measurements can also be used to estimate biomass. The sensitivity of CRNS neutron counts to SWC in the early season (before blooming) was twice as high as that during the mid- and late growing seasons (maximum leaf cover). The Cornish Pasdy model­, which models the measured neutron counts as a function of SWC and biomass contribution, was calibrated and then inverted to estimate the biomass in the cherry and olive tree orchards. 

How to cite: Al-Mashharawi, S. K., El Hajj, M. M., Johansen, K., McCabe, M. F., and Steele-Dunne, S.: Sensitivity of the Cosmic Ray Neutron Sensor (CRNS) to Seasonal Biomass Dynamics in Cherry and Olive Orchards, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6789, https://doi.org/10.5194/egusphere-egu23-6789, 2023.

Galactic cosmic rays (GCR) are energetic particles originating from galactic or extra-galactic sources. When they arrive inside our heliosphere, they are modulated by the magnetic irregularities in the solar wind flow from the Sun, deflecting and slowing down the GCR particles. The level of this modulation varies according to solar activity, especially the 11-year solar cycle. The heliospheric modulation potential, denoted by ϕ, describes the average energy loss of particle in MV and quantifies the level of modulation. It can be determined using ground-based neutron monitor (NM) measurements of GCRs by multiple stations. Here we use the most recent version of the NM yield function and a RMSE-minimization method to compute a new and more accurate version of the modulation potential ϕ and station-specific scaling factors κ, which can be used to scale the level of count rates to the theoretical NM count rate given by the model. The new version offers daily resolution of ϕ and can be conveniently updated with new measurements, stations, or updates to datasets whenever they might occur. The scaling factors and their variation can be used to scale the data for physical analyses or to identify outliers, errors or physical phenomena which do not match with the model.

How to cite: Väisänen, P., Usoskin, I., Kähkönen, R., Koldobskiy, S., and Mursula, K.: Updated heliospheric modulation potential of cosmic rays and station-specific scaling factors for 1964-2021, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11071, https://doi.org/10.5194/egusphere-egu23-11071, 2023.

Monitoring soil moisture at depths greater than one meter is generally challenging and often highly invasive as it requires opening large soil pits. As a result, this deeper vadose zone is often not monitored at all. On top of that, conventional soil moisture sensors usually have only a small measurement volume. On the other hand, soil moisture estimates derived from above-ground Cosmic-Ray Neutron Sensing (CRNS) are a representative average over an area of several hectares but only of the upper half meter of the soil. To this day, it is commonly believed that cosmic radiation cannot be used to monitor soil water content below this depth. As a consequence, large parts of the root-zone and deeper unsaturated zone have remained outside the observational window of the method. The estimation of soil moisture in greater depths typically requires additional invasive measurements, other active geophysical methods, or mathematical models which extrapolate surface soil moisture observations.

Against this background, we investigated the possibility of using passive detection of cosmogenic neutrons in existing monitoring infrastructure (e.g. groundwater wells). We hypothesized that this method provides a larger measurement volume than traditional techniques based on active neutron probes while requiring less safety restrictions.

Our neutron transport simulations demonstrated that this downhole-CRNS technique would be sensitive enough to detect changes of water content in depths down to 5 meters and above, depending on the temporal resolution of measurements. The simulations also revealed a large measurement radius of several tens of cm depending on the soil moisture content and soil bulk density.

From the theoretical results we derived a functional relationship between soil moisture and detectable neutrons and tested it in a groundwater observation well. Additional installations of supporting soil moisture sensors have been used to validate the model predictions as well as the neutron signals monitored by the CRNS detector. The study demonstrated the general applicability of downhole Cosmic-Ray Neutron Sensing for the estimation of soil moisture in greater depths and at temporal resolution of two days.

How to cite: Rasche, D., Weimar, J., Schrön, M., Köhli, M., Morgner, M., Güntner, A., and Blume, T.: Monitoring soil moisture in the deeper vadose zone: A new approach using groundwater observation wells and cosmic ray neutrons, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11326, https://doi.org/10.5194/egusphere-egu23-11326, 2023.

Experiments during recent years with SEVAN detectors on mountain tops in Armenia, Slovakia, and Bulgaria reveal the broad potential of SEVAN detectors; The SEVAN detector on Lomnicky Stit (Slovakia) measured the largest thunderstorm ground enhancements (TGE), with particle fluxes exceeding the background 100-times. With muon and gamma ray fluxes, the maximum values of the potential difference in thunderclouds were measured, equal to 350 MV at Mt. Aragats, and 500 MV at the sharp peak of Lomnicky Stit. In Nov 2019, SEVAN detectors were installed at DESY (Hamburg and Zeuthen sites). Fluxes of electrons, photons, and muons and weather parameters are continuously monitored at all sites (at different latitudes, longitudes, and altitudes). To fully exploit the scientific potential of the SEVAN detectors, in 2023 is planned to install a new detector in the Umwelt-Forschungs-Station (UFS, Schneefernerhaus, 2650 m asl) near the top of the Zugspitze (2962 m), a site with a long history of atmospheric research. The new SEVAN module will be compact (SEVAN-light), and will enable the energy spectra measurements in the range from 0.3 to 50 MeV, allowing unambiguously separating Radon progeny gamma radiation from runaway electron-photon avalanches.

How to cite: Karapetyan, T., Chilingarian, A., and Sargsyan, B.: SEVAN European particle detector network for the atmospheric, solar and space weather studies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11905, https://doi.org/10.5194/egusphere-egu23-11905, 2023.

Neutron monitor counting rates show, among others, a  $\sim$ 1.6--2.2-year period. This period has been associated with a solar origin affecting the cosmic ray propagation conditions through the heliosphere. The duration of this period varies from one Solar Cycle to another.
\cite{Comazzi_Blanco_2022} found the duration of the $\sim$ 1.6--2.2-year period ($\tau$) is linearly related to the averaged sunspot number ($SSN_a$) in each Solar Cycle.
In this piece of research, we have analyzed this relationship. This equation shows that shorter $\sim$1.6--2.2-year periods occur during stronger cycles when $SSN_a$ is higher. Drawing on this relationship given by $SSN_a = (-130 \pm 10) \: \tau + (330 \pm 30)$, we computed $\tau$ for the cycles previous to the existence of neutron monitors (Solar Cycles 7--19). 
By means of the Huancayo neutron monitor spectrum we checked the validity of this equation along the Solar Cycle 19. 
Once the previous relationship is checked, $\tau$ for the current Solar Cycle 25 is computed giving $\sim$ 2.22 years.

An internal mechanism of the solar dynamo called Rossby waves could produce these variations in the solar magnetic field  and, indirectly, in neutron monitor counting rates.
The harmonic of fast Rossby waves with $m=1$ and $n=8$ fit with the detected periodicity and the variation of the solar magnetic field strength from weaker to stronger Solar Cycles could explain the different periods detected in each cycle.
Finally, a solar magnetic field strength of $\sim$ 7--25 kG in the tachocline have been estimated based on the detected periodicities using the dispersion relation for fast Rossby waves. 

How to cite: López-Comazzi, A. and Blanco-Ávalos, J. J.: Study of the relationship between Sunspot number and the duration of the $\sim$1.6--2.2-year period in neutron monitor counting rates, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11981, https://doi.org/10.5194/egusphere-egu23-11981, 2023.

Epithermal neutrons from cosmic ray showers are slowed by hydrogen atoms in snow. The drop in the fast neutron abundance in the atmosphere can be measured with above-ground Cosmic Ray Neutron Sensing (CRNS), allowing for an estimation of the Snow Water Equivalent (SWE). SWE is an important variable that has a substantial role in hydrological modelling and forecasts. However, up to now, SWE is conventionally measured at point-scale, which holds only little information about the average SWE in areas of heterogeneous terrain and where snow drift is a predominant process. CRNS offers the prospect of closing this gap by sensing neutrons within a footprint of 10–20 hectares. Currently, further investigations are needed to reduce the uncertainties in the signal conversion from neutron counts to SWE. In this study, we compare the daily signals of 65 CRNS stations across Europe with the corresponding Fractional Snow Cover (FSC) products from Sentinel-2 and MODIS (Moderate-resolution Imaging Spectroradiometer) with a 20 m and 500 m spatial resolution, respectively. By analysing the FSC products, we were able to identify characteristic ranges of neutron counts at snow presence (winter signals) and absence (summer signals). Comparing these ranges and their overlap among stations, we were able to distinguish typical signal properties of lowland, pre-Alpine and Alpine sites. We found that altitude-related properties, such as soil and vegetation characteristics govern the general neutron level at the study sites. Snowfall typically leads to a major drop in the neutron count rate that is superimposed on the summer neutron count level. High-altitude stations are generally characterized by low ranges of count rates in summer and by high ranges in winter, while low-altitude stations show a reversed trend. Our results demonstrate that the suitability of a station for SWE measurements with CRNS depends highly on the site-specific hydrogen pool fluctuations that can be linked to altitude. Especially in heterogeneous mountain terrain with low soil formation, the advantages of CRNS come into play and can provide a spatial average of SWE with low uncertainties.

How to cite: Krebs, N., Schattan, P., Oswald, S., Schrön, M., Rutzinger, M., and Stötter, J.: Cosmic rays on snow: A combined analysis of fractional snow cover derived from Sentinel-2, MODIS and Cosmic Ray Neutron Sensors across Europe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12576, https://doi.org/10.5194/egusphere-egu23-12576, 2023.

Neutron monitors are ground-based devices that measure the secondary particle population, i.e., neutrons produced by, e.g., galactic cosmic rays (GCRs). Due to their functionality, they are integral counters whose flux is proportional to the variation of the input spectrum. However, the measured flux also depends on the geomagnetic position and the static pressure at the monitor's location. To better understand the instrument response, the Christian-Albrechts-Universität zu Kiel, DESY Zeuthen, and the North-West University in Potchefstroom, South Africa, agreed on regular monitoring of the GCR intensity as a function of latitude, by installing a portable device aboard the German research vessel Polarstern in 2012. The vessel is ideally suited for this research campaign because it covers extensive geomagnetic latitudes (i.e., goes from the Arctic to the Antarctic) at least once per year. Since the installation aboard the vessel, 12 latitude scans were performed, allowing us to compute the so-called yield function by experimental means presented in this contribution.

The Kiel team received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 870405. The team would like to thank the crew of the Polarstern and the AWI for supporting our research campaign.

How to cite: Heber, B., Burmeister, S., Giese, H., Herbst, K., Romaneehsen, L., Schwerdt, C., Strauss, D. T., and Walter, M.: Measurements of cosmic rays by a mini neutron monitor aboard the German research vessel Polarstern, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15343, https://doi.org/10.5194/egusphere-egu23-15343, 2023.

Neutron monitors on the Earth’s surface are usually used to observe the dynamics of highly energetic cosmic-ray particles, assuming that local environmental conditions do not influence the measurement. In another young research field, low-energy cosmic-ray neutrons are used to monitor local dynamics of environmental water content. Water in soil, air, snow and vegetation determines the amount of ground albedo neutrons in the sensitive energy range from 1 eV to 100 keV. Plenty of small neutron detectors are operated on natural or agricultural sites all around the world. 

A major issue is the modulation of the neutron flux by the dynamics of incoming high-energy cosmogenic particles. Conventionally, independent data from neutron monitors are consulted to serve as a reference for the correction of the local detectors. However, the performance of this comparative correction approach is unreliable, because it does not account for geographical displacement, different energy windows of the detectors, or potential influence of atmospheric conditions on the referenced neutron monitor.

To test the traditional correction approaches for incoming cosmic radiation, air pressure, and air humidity, an experimental setup should avoid any influence of changes due to soil moisture. Therefore, a set of neutron detectors have been deployed in a buoy at the center of a lake for six months. The measurement period also included a Forbush Decrease in September, 2014. 

We found that the neutron signals correlated with air pressure, air humidity, and secondary cosmic radiation. The thermal neutron response to air humidity has been revealed to be different from the epithermal neutron response, while air pressure and incoming radiation similarly   influenced the thermal and epithermal signals. The results have been used to evaluate different existing strategies for air humidity correction of low-energy neutron data. Additionally, the potential effect of lake temperature on the thermal neutron count rate has been investigated. We have also analyzed the performance of the buoy  signal together with different neutron monitors in their capability to correct for the changes of incoming radiation and for the Forbush Decrease during the measurement period.

Overall, the study demonstrates how low-energy neutron detectors on a buoy  could be used to assess the influence of atmospheric and cosmogenic factors on the signal without the influence of soils. Despite the low count rate over water, the general principle could also serve as an alternative to remote neutron monitors as a more local reference signal at more comparable energies.

How to cite: Schrön, M., Rasche, D., Weimar, J., Köhli, M., Boehrer, B., Dietrich, P., and Zacharias, S.: Buoy-based detection of low-energy cosmic-ray neutrons to monitor the influence of atmospheric effects, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15523, https://doi.org/10.5194/egusphere-egu23-15523, 2023.

The GRAPES-3 muon telescope (G3MT) has been recording high statistics of muons at a rate of ~50000 per second for the past two decades allowing us to probe the tiny variations in the muon flux caused by solar phenomena. The directional capabilities of G3MT enable us to look into 169 independent directions with a large median rigidity ranging from 64 to 141 GV. We have examined the 22 years (2000-2021) of G3MT data using the Fourier series technique to obtain the daily SDA amplitude and phase. The measured SDA amplitude and phase show a strong rigidity dependence. We found that the phase dominantly has the 22-year variation controlled by the drift effect due to solar polar magnetic field reversal, regardless of their rigidity. However, the higher rigidity bin phase variation shows an additional component of the 11 years controlled by the diffusion. The details of this work will be discussed during the talk.

How to cite: Zuberi, M. and the The GRAPES-3 Collaboration: Rigidity dependence of cosmic ray diurnal anisotropy using 22 years of GRAPES-3 muon telescope data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15741, https://doi.org/10.5194/egusphere-egu23-15741, 2023.

The Earth is continuously exposed to galactic cosmic rays. The magnetized solar wind in the heliosphere and the Earth's magnetic field alters the flux of these particles. If cosmic rays hit the atmosphere, they can form secondary particles. The total flux measured within the atmosphere depends on the atmospheric density above the observer. Therefore, the ability of a particle to approach an aircraft depends on its energy, the altitude, and the position of the plane. The cutoff rigidity describes the latter.
The radiation detector of the detector system NAVIDOS (NAVIgation DOSimetry) is the DOSimetry Telescope (DOSTEL), measuring the count and dose rates in two semiconductor detectors. From 2008 to 2011, two instruments were installed in two aircraft. First, we corrected the data for pressure variation by normalizing them to one flight level and determined their dependence on the cutoff rigidity by fitting a Dorman function to the observation. The latter was used to compute the yield function, which describes the ratio of incoming primary cosmic rays, approximated by a force field solution, to the measured count and dose rate for a particular instrument. As for neutron monitors, the sensitivity increases substantially above a rigidity of about 1 GV.
We received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 870405. 

How to cite: Romaneehsen, L., Burmeister, S., Giese, H., Heber, B., and Herbst, K.: Yield function of the DOSimetry TELescope (DOSTEL) count and dose rates aboard an aircraft, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15980, https://doi.org/10.5194/egusphere-egu23-15980, 2023.

Cosmic ray neutron sensor (CRNS) technology is becoming increasingly popular for monitoring volumetric soil water content (SWC) at the field (hectare) scale in a variety of environments. Applications include permanently installed (stationary) or the use of mobile (rover, trains, etc.) platforms. In agricultural settings, permanently installed CRNS have proven particularly useful for providing time series of footprint average SWC estimates. To derive the SWC product at a site, CRNS needs to be calibrated using gravimetric SWC, soil organic matter and bulk density (BD). Those variables may in the best case be derived from a large number of soil samples, collected ideally on multiple occasions and under a range of hydrometeorological conditions. Most CRNS applications use an average site-specific value of bulk density derived for a site from ≥1 field calibration and it is considered static over time.

However, while this is a safe assumption for many environments, in agricultural settings, management activities (e.g. tillage) may introduce substantial changes in BD over time. This may affect the accuracy of the CRNS SWC estimates, which in turn could affect management decisions (e.g. on irrigation) or modelling efforts, relying on these SWC inputs.

The importance of BD as a source of uncertainty in CRNS SWC estimation has been recognized with dedicated laboratory and neutron simulation experiments quantifying the effects. However, field-based studies are lacking. Therefore, the objective of this work is to quantify the impact and relevance of temporal variability in soil bulk density on the estimation of CRNS SWC in a variety of environments with different level of agricultural land use management. We used data from three sites (Scotland, Germany and China) with stationary CRNS, where BD was sampled on ≥3 or more occasions for sensor calibration. The sites display a varying intensity of land use management, cover different soil types and contrasting weather conditions. We quantify the differences in estimates of SWC by using the range of average BD values at a site and compare these differences to other sources of uncertainty (e.g. the integration time of neutron counts). We additionally consider existing theories on the interaction of neutrons and soil bulk density to evaluate the impact of BD changes. Finally, we make recommendations on when BD variability and thus its sampling over time may become important for the derivation of CRNS SWC outputs.

How to cite: Dimitrova Petrova, K., Scheiffele, L., Verrot, L., Schrön, M., and Geris, J.: Impact and relevance of soil density changes on cosmic-ray neutron sensing for soil water estimation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16004, https://doi.org/10.5194/egusphere-egu23-16004, 2023.

Cosmic Ray Sensors (CRS) are used worldwide to measure soil moisture at intermediate scales, exploiting the neutrons produced in the air showers created by cosmic ray particles interacting with the atmosphere. Neutron Monitors also exploit these atmospheric neutrons, but they are shielded from local soil moisture variations so that information about the cosmic ray flux near Earth can be deduced from their observations. Neutron monitors remain the state of the art for observing variations in high-energy cosmic rays and are critically important to understanding ground-level enhancements of atmospheric radiation caused by high energy solar energetic particles.

This contribution explores how the UK CRS network (COSMOS-UK) can complement the neutron monitor network in monitoring these ground-level enhancements, as well as other space weather-driven variations in the ground-level neutron flux. Observations of such variations using COSMOS-UK are presented and discussed, and the sensitivity of COSMOS-UK to ground-level enhancements is also shown. Finally, the prospects and challenges of improving the space weather utility of CRS networks are discussed.

How to cite: Baird, F. and Ryden, K.: Cosmic Ray Soil Moisture Sensors as an Asset to Space Weather Monitoring Activities, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17336, https://doi.org/10.5194/egusphere-egu23-17336, 2023.

³He gas proportional counters have an extensive history in planetary neutron spectroscopy and several upcoming missions including Psyche, VIPER, MMX and Dragonfly will include this technology. In space, Galactic Cosmic Ray (GCR) protons deposit energy in the ³He gas in these detectors via ionization. This energy deposition constitutes a background on top of the neutron capture pulse-height spectrum that is particularly prominent at low energies. As planetary nuclear spectroscopy experiments are often count-rate limited using the full pulse height spectrum, including the proton and triton wall effect regions, has significant value. This will be particularly true for the upcoming VIPER mission that will explore the permanently shaded regions at the Moon’s south pole using the Neutron Spectrometer System (NSS).  The NSS does not include a neutron generator, so the count rates are low, and the rover will not spend long at any location.  However, using lower-energy parts of the spectrum requires understanding the GCR-originating background, which none of the previous missions were able to measure due to their low-energy cutoffs. GCR protons with mean energy around 400 MeV deposit similar amounts of energy to the 4 GeV mean-energy muons present at ground level as both represent minimum ionizing particles within the 3He sensors.  We therefore developed an experiment using a pair of plastic scintillators in coincidence with a ³He tube to measure energy deposition from muons while excluding room background gamma rays.  Here we will present results of this experiment to characterize the angular response to cosmic ray muons of a ³He flight spare detector from the VIPER NSS and explore the implications of these results for analysis of planetary neutron data sets.

How to cite: Wilson, J. T., Peplowski, P. N., Yokley, Z. W., Lawrence, D. J., and Elphic, R. C.: Cosmic ray muons as a proxy for in-cruise galactic cosmic ray protons in 3He gas proportional counters, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17421, https://doi.org/10.5194/egusphere-egu23-17421, 2023.

Cosmic-ray neutron sensors buried below a snow pack provide a passive and autonomous monitoring technique of snow water equivalent (SWE). The effective neutron flux is attenuated inside the snow volume resulting in an inverse relationship between neutron intensity and the water equivalent of the snow column above the sensor. Neutrons are moderated and absorbed within the snow. Simultaneously, highly energetic cosmic rays produce further neutrons via spallation and evaporation processes. A comprehensive assessment of the neutron flux therefore requires multi-particle simulations which involve all relevant incoming particle species and transient particles from cosmic-ray showers which play a crucial role in neutron production.

In our study, we used the Monte Carlo toolkit MCNP6 and validated its high-energy evaporation and spallation models against a measured data set of a neutron intensity profile in water. Based on that we fitted analytical functions to a large variety of simulation setups that describe the neutron intensity as a function of SWE and the moisture content of the soil below the sensor. Moreover, single-particle tracking revealed that the radial footprint of the method does not exceed few meters for detectors below thick snow layers. In the case of shallow snow, however, the diffusive long-range neutron flux in the atmosphere may penetrate through the snow pack to the buried sensor and thereby increases the influence of distant objects. Since the diffusive flux is further sensitive to the atmospheric water content, we developed an air humidity correction tailored to snow-buried neutron detectors.

In general, the study aims at a holistic understanding of neutron production and transport processes in snow and the adjacent soil and air volumes in order to improve SWE monitoring by buried cosmic-ray neutron sensors and compares the simulation results to field data.

How to cite: Weimar, J., Schattan, P., Gugerli, R., Fersch, B., Desilets, D., Schrön, M., Köhli, M., and Schmidt, U.: Cosmic-ray neutron production and propagation inside snow packs characterized by multi-particle Monte Carlo simulations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17487, https://doi.org/10.5194/egusphere-egu23-17487, 2023.

The magnetosheath is a region downstream of the bow shock filled with turbulent, decelerated solar wind plasma which is flowing earthwards. This solar wind flow sometimes shows signatures of localized structures with enhanced dynamic pressure, so called magnetosheath jets. These jets are often  associated with low angles between the bow shock normal and the interplanetary magnetic field (IMF) direction, the so called quasi-parallel bow shock. Less often they are also found behind the quasi-perpendicular bow shock.

As jets propagate through the magnetosheath, they interact with the surrounding plasma. Studying waves inside, and in the vicinity of, jets is a step towards understanding the interaction of jets with the surrounding plasma. So far whistler waves, electrostatic waves, waves in the lower hybrid frequency range as well as low frequency waves have been reported. However, the sources of these waves are unknown. In addition, further types of waves may be associated with the jets.

We conduct a study on waves in magnetosheath jets using burst mode data of the Magnetospheric Multiscale (MMS) mission. The magnetic and electric field data are provided with a sampling rate of 8 kHz, while previous studies used data sets with much lower sampling rates. The high time resolution allows us to study different waves over a large frequency range and investigate properties of these waves. In addition, we discuss possible generation mechanisms.

How to cite: Krämer, E., Hamrin, M., Gunell, H., Karlsson, T., Steinvall, K., Goncharov, O., and André, M.: Identifying the zoo of waves in Magnetosheathjets using MMS burst data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-550, https://doi.org/10.5194/egusphere-egu23-550, 2023.

The interaction between the solar wind and Earth’s magnetic field results in the formation of a supercritical bow shock. Downstream of this shock wave, the magnetosheath region emerges, in which high-speed plasma flows can be formed.  These jets have been connected to several shock and foreshock properties. Moreover, due to their unique properties (i.e., higher density and velocity compared to the ambient flow), they can cause a variety of different phenomena, including magnetopause reconnection, excitation of ULF waves and electron acceleration.

In this work, we use Magnetosphere Multiscale (MMS) mission to demonstrate jets’ complex structure by investigating their velocity distribution functions. Specifically, we focus on how their VDFs change over time and on whether they exhibit non-Maxwellian properties. By comparing with the VDFs taken from the background magnetosheath, we show that full particle plasma moments provide an inadequate description of jet plasma properties. Furthermore, we present different metrics to quantify the non-Maxwellian features exhibited by jet observations. Finally, we discuss how the observed kinetic properties of jets may provide insight into jets generation, wave excitation and evolution.

How to cite: Raptis, S., Karlsson, T., Vaivads, A., Lindberg, M., and Trollvik, H.: Velocity distribution functions and non‐Maxwellianity of magnetosheath jets using MMS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-929, https://doi.org/10.5194/egusphere-egu23-929, 2023.

Magnetosheath jets are a class of phenomena that are usually defined as structures of enhanced dynamic pressure in the magnetosheath. The origins of some jets have been traced back to steepening ULF waves in the foreshock, but other formation mechanisms have also been described. In this study we use four 2D simulation runs of the global magnetospheric hybrid-Vlasov simulation Vlasiator to investigate the formation of magnetosheath jets at the bow shock. We use 2D views of the simulation and virtual spacecraft to investigate the plasma and magnetic field properties around and at the times and locations of jet formation. We find that of the 796 jets analysed this way, 91% appear to form in association with foreshock structures of enhanced dynamic pressure impacting the bow shock. These jets mainly form downstream of the ULF foreshock, while the remaining 9% are generally found near the ULF foreshock edges toward the flanks and have different properties from the foreshock structure-associated jets.

How to cite: Suni, J., Palmroth, M., Battarbee, M., Turc, L., Alho, M., Cozzani, G., Dubart, M., Ganse, U., George, H., Gordeev, E., Grandin, M., Horaites, K., Papadakis, K., Pfau-Kempf, Y., Tarvus, V., Tesema, F., Zaitsev, I., and Zhou, H.: Study of the Local Bow Shock Environment during Magnetosheath Jet Formation: Vlasiator Results, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1222, https://doi.org/10.5194/egusphere-egu23-1222, 2023.

Temperature anisotropy-driven instabilities such as the mirror mode and ion cyclotron instabilities are responsible for the generation of waves in the turbulent magnetosheath of planets. We present two statistical studies of mirror mode-like structures in the magnetosheaths of (mostly) unmagnetised planets such as Mars and Venus, characterised in the same way and with the same tools with the help of on-board magnetometers. In this presentation, we discuss observations by the MAVEN spacecraft. As in our companion Venus study (see poster by Volwerk et al. in the same session), we use magnetic field-only measurements to constrain and identify these quasi-linear compressive structures and discuss ways to mitigate false positive detections based on one instrument only. After calculating the residence time of the spacecraft in the Martian magnetoenvironment, we show two-dimensional statistical maps of mirror mode-like occurrence rates with respect to EUV solar flux levels, Mars Year, and atmospheric seasons. We find detection probabilities of about 1% at most, with two main regions of occurrence, one behind the collisionless shock, the other close to the induced magnetospheric boundary, with the clearest modulation of the probability due to EUV solar flux conditions. Finally, we qualitatively compare our results with past studies at Mars.

How to cite: Simon Wedlund, C., Volwerk, M., Mazelle, C., Rojas Mata, S., Stenberg Wieser, G., Futaana, Y., Halekas, J., Rojas-Castillo, D., Bertucci, C., and Espley, J.: Mirror mode-like structures around unmagnetised planets: 1. Mars as observed by the MAVEN spacecraft, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1305, https://doi.org/10.5194/egusphere-egu23-1305, 2023.

Temperature anisotropy-driven instabilities such as the mirror mode and ion cyclotron instabilities are responsible for the generation of waves in the turbulent magnetosheath of planets. We present here a statistical study of mirror mode-like structures in the magnetosheath of Venus as observed by the Venus Express spacecraft. As in our Mars study (see poster by Simon Wedlund et al. in the same session), we use magnetic field-only measurements to constrain and identify these quasi-linear compressive structures and discuss ways to mitigate false positive detections based on one instrument only. After calculating the residence time of the spacecraft in the Venusian magnetoenvironment, we show two-dimensional statistical maps of mirror mode-like occurrence rates with respect to EUV solar flux levels, and type of bow shock (quasi-perpendicular vs quasi-parallel). We find detection probabilities of about 10% at most, with two main regions of occurrence, one behind the collisionless shock, the other close to the induced magnetospheric boundary, with the small modulation of the probability due to EUV solar flux conditions.

How to cite: Volwerk, M., Simon Wedlund, C., Mautner, D., Rojas Mata, S., Stenberg Wieser, G., Futaana, Y., Fraenz, M., Mazelle, C., Rojas-Castillo, D., Bertucci, C., and Delva, M.: Mirror mode-like structures around unmagnetised planets: 2. Venus as observed by the Venus Express spacecraft, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1532, https://doi.org/10.5194/egusphere-egu23-1532, 2023.

How to cite: Lu, X., Zhang, H., Otto, A., Liu, T., and Chen, X.: The bow shock and magnetosheath responses to density depletion structures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2438, https://doi.org/10.5194/egusphere-egu23-2438, 2023.

We have investigated approximately four years of MESSENGER data to identify short, large-amplitude magnetic structures (SLAMS) in the Mercury foreshock. Defining SLAMS as well-defined structures with a magnetic field strength of at least a factor of 3 higher than the background magnetic field, when MESSENGER is located in the solar wind, we find 435 SLAMS. The SLAMS are found either in regions of a general ultra-low frequency (ULF) wave field, at the boundary of such a ULF wave field, or isolated from the wave field. We invetigate several properties of the SLAMS, such as temporal scale size, amplitude, and polarization. We find that SLAMS are mostly found during periods of low interplanetary magnetic field strength, indicating that they are more common for higher solar wind Alfvénic Mach number (M_A). We use the Tao solar wind model to estimate solar wind parameters to verify that M_A is indeed larger during SLAMS observations than otherwise. Finally, we also investigate how SLAMS observations are related to foreshock geometry.

How to cite: Karlsson, T. and Plaschke, F.: MESSENGER observations of short, large-amplitude magnetic structures (SLAMS) in the Mercury foreshock, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2702, https://doi.org/10.5194/egusphere-egu23-2702, 2023.

The shock wave is a primary interface for plasma heating and charged particle acceleration. In collisionless solar wind plasma, such acceleration is attributed to the wave-particle resonant interactions. This letter focuses on electron acceleration by one of the most widespread high-frequency electromagnetic wave emissions, whistler-mode waves. Using spacecraft observations of the Earth's foreshock transient, we demonstrate that intense whistler-mode waves may resonate nonlinearly with $\sim 10-100$eV solar wind electrons and accelerate them to $\sim 100-500$eV. Accelerated electron population has a butterfly pitch-angle distribution, in agreement with theoretical predictions. The presented evidence of the efficiency of nonlinear resonant acceleration suggests that this mechanism may play an important role in solar wind electron injection into the shock-drift acceleration.

How to cite: Shi, X., Artemyev, A., Angelopoulos, V., Liu, T., and Zhang, X.-J.: Electron acceleration by intense whistler-mode waves at foreshock transients, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2963, https://doi.org/10.5194/egusphere-egu23-2963, 2023.

Plasma structures with the enhanced dynamic pressure, density or speed are often observed in the Earth’s magnetosheath. These structures, known as jets and fast plasmoids, can be registered in the magnetosheath, downstream both the quasi-perpendicular and quasi-parallel bow shocks (BS). Using measurements by the Magnetospheric Multiscale (MMS) spacecraft, Goncharov et al. (2020) showed similarities in the plasma properties of the jets and fast plasmoids. However, they pointed out that the different magnetic fields inside the structures suggest that the formation mechanisms are different. Hybrid simulations by Preisser et al. (2020) have shown differences in the mechanisms of jet and embedded plasmoid formation. On the other hand, structures registered close to the BS/magnetopause or in the sub-solar/flank magnetosheath are not fully the same. Based on our comparative analysis, we discuss features of jet-like structures, their properties, occurrence, evolution, and relation to the magnetosheath parameters.

How to cite: Goncharov, O., Šafránková, J., Němeček, Z., and Xirogiannopoulou, N.: Jet-like structures in different regions of the magnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3155, https://doi.org/10.5194/egusphere-egu23-3155, 2023.

The turbulent foreshock region upstream of the quasi- parallel bow shock is dominated by waves and reflected particles that interact with each other and create a large number of different foreshock phenomena. The plasma structures with the enhanced magnetic field (Short Large Amplitude Magnetic Structures, SLAMS), and density spikes, named plasmoids, are frequently observed. They are one of the suggested sources of transient flux enhancements (TFE) or jets in the magnetosheath. Using measurements of the Magnetospheric Multiscale Spacecraft (MMS) and OMNI solar wind database between 2015 and 2018 years, we have found that there is a category of events exhibiting both magnetic field and density enhancements simultaneously and we introduce the term “mixed structure” for them. Consequently, we divided our set of observations into three groups and present a comparative statistical analysis in the subsolar foreshock. Based on our results and previous research, we discuss their properties, possible origin, occurrence rate under different upstream conditions and their relation to the jets and plasmoids in the magnetosheath. We suggest that plasmoids and SLAMS are different phenomena created in the foreshock under different upstream conditions and that the enhanced density, rather than magnetic field magnitude, is principal for creation of magnetosheath jets.

How to cite: Xirogiannopoulou, N., Goncharov, O., Šafránková, J., and Němeček, Z.: Characteristics of foreshock subsolar compressive structures and their connection to magnetosheath jet-like phenomena, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3199, https://doi.org/10.5194/egusphere-egu23-3199, 2023.

Mirror mode waves with anticorrelated density and magnetic field perturbations have been widely observed in the planetary magnetosheaths and solar wind. In this study we examine the time evolution of proton mirror instability based on the hybrid particle simulation with the focus being on the thermodynamics of mirror waves. A set of double-polytropic (DP) laws are adopted to infer the corresponding thermodynamic conditions characterized by the polytropic exponents, γ_⊥and γ. It is shown that the γ_⊥, values at the saturation stages are in the ranges of γ_⊥ = 0.64±0.21 and γ = 1.07±0.12 which are consistent with the observations and linear kinetic theory (Hau et al. 2021). The saturated plasma β are well fitted by the modified DP MHD mirror condition of γβ = β_⊥²/(2+γ_⊥β_⊥) with γ_⊥ ≈ 0.8, γ ≈ 1.3 which may be used as a new mirror criterion for the mirror waves observed in the solar system.

How to cite: Chang, C.-K. and Hau, L.-N.: Kinetic simulation of proton mirror instability, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3758, https://doi.org/10.5194/egusphere-egu23-3758, 2023.

In the foreshock region of planetary and terrestrial bow shocks, interaction of reflected solar wind ions with the incident solar wind and the interplanetary magnetic field gives rise to a variety of transient plasma structures and instabilities, and the ion dynamics and ion kinetic scale processes drive the foreshock environment. In this comparative study, we consider specific examples of transient foreshock structures upstream of Mars and Earth and contrast differences between theri formation process, contributing ion populations, and source region of ion populations. Due to the smaller size of Mars and its bow shock compared to Earth and with respect to upstream ion convective gyroradius, reflected ions with hybrid trajectories that straddle between the quasi-perpendicular and quasi-parallel bow shocks can contribute to formation of foreshock transients. The size of transient foreshock structures upstream of Mars differs compared to Earth, which influences their propagation and impact through the magnetosheath and lower plasma boundaries.

How to cite: Madanian, H.: Formation of Transient Foreshock Structures Upstream of Mars and Earth: A Comparative Study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4004, https://doi.org/10.5194/egusphere-egu23-4004, 2023.

Magnetic holes are significant depressions of the interplanetary magnetic field (IMF) that can be found embedded in the solar wind everywhere within the heliosphere. They resemble mirror mode magnetic structures that form as a response to excess perpendicular temperatures. Magnetic holes situated at IMF discontinuities (current sheets) may also be the result of reconnection. Magnetic holes occur more often under fast solar wind conditions, and their scale sizes are known to be on the order of thousands to tens of thousands of km, determined essentially from temporal width and plasma velocity observations. So far, the scale sizes have only been estimated for the directions parallel to the respective solar wind plasma flows. In this study, we attempt to calculate the first distributions of the scale sizes for the orthogonal, flow-perpendicular directions. Therefore, we use multi-point observations of magnetic holes by the ARTEMIS spacecraft in lunar orbit. The method we use has been previously applied to plasma jets present in the magnetosheath of Earth. The knowledge of the flow-perpendicular scale sizes is important to assess the holes’ impact on planetary magnetospheres and cometary environments.

How to cite: Plaschke, F., Volwerk, M., Karlsson, T., Götz, C., Heyner, D., Hietala, H., Mieth, J. Z. D., Schmid, D., Simon-Wedlund, C., and Vörös, Z.: On the scale sizes of magnetic holes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4366, https://doi.org/10.5194/egusphere-egu23-4366, 2023.

Modeling the interaction of solar wind discontinuities with the bow shock-magnetosheath-magnetopause system is an important step in comprehending the effects of solar wind structures on the magnetosphere. Our procedure is to first run a global MHD simulation to predict the overall configuration of the solar wind-magnetosphere system before the discontinuity interacts with the bow shock. Then fields and plasma moments within a large sub-domain of the global MHD simulation are used to set the initial conditions of an implicit PIC simulation of the interaction of the discontinuity with the dayside magnetosphere. This procedure allows us to follow the evolution of kinetic processes as the discontinuity interacts with the bow shock and propagates through the magnetosheath before impacting the dayside magnetopause. In this presentation, we show some results of the interaction of a rotational discontinuity where the interplanetary magnetic field, initially southward, turns northward. As expected, the discontinuity slows down abruptly after interacting with the bow shock, the transverse component of the magnetic field being greatly enhanced in the process.  While the initial MHD state of the magnetosheath was laminar, kinetic waves and instabilities lead to a turbulent state for all plasma moments and electromagnetic fields. In particular, transients are observed ahead of the discontinuity as it propagates Earthward. At later stages of the simulation, the discontinuity interacts with the magnetopause. Magnetic field lines are bent strongly in the transverse direction, affecting reconnection processes with the production of large magnetic flux ropes.

How to cite: Berchem, J., Lapenta, G., Escoubet, P., and Wing, S.: Kinetic modeling of the interaction of solar wind discontinuities with the bow shock-magnetosheath-magnetopause system, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4522, https://doi.org/10.5194/egusphere-egu23-4522, 2023.

The foreshock, extending upstream of the quasi-parallel shock and populated with shock-reflected particles, is home to intense wave activity in the ultra-low frequency range. The most commonly observed of these waves are the '30-second' waves, fast magnetosonic waves propagating sunward in the plasma rest frame, but carried earthward by the faster solar wind flow. These waves are thought to be the main source of Pc3 magnetic pulsations (10-45 s periods) in the dayside magnetosphere, but how the waves can transmit through the bow shock and across the magnetosheath had remained unclear. Global hybrid-Vlasov simulations performed with the Vlasiator model provide us with the global view of foreshock wave transmission across near-Earth space. We find that the foreshock waves modulate the plasma parameters just upstream of the bow shock, which in turn periodically changes the shock compression ratio and the downstream pressure. This launches fast-mode waves propagating through the magnetosheath all the way to the magnetopause, where they can further transmit into the dayside magnetosphere. We compare our numerical results with MMS observations near the subsolar point, where we identify earthward-propagating fast-mode waves at the same period as the foreshock waves, consistent with our simulation results. Our findings show that the wave propagation across the bow shock is much more complex than the simple direct transmission of the foreshock waves which was inferred in early studies.

How to cite: Turc, L., Roberts, O. W., Verscharen, D., Dimmock, A. P., Kajdic, P., Palmroth, M., Pfau-Kempf, Y., Johlander, A., Dubart, M., Kilpua, E. K. J., Takahashi, K., Takahashi, N., Battarbee, M., and Ganse, U.: Transmission of foreshock waves through Earth's bow shock, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6637, https://doi.org/10.5194/egusphere-egu23-6637, 2023.

Linear magnetic holes (LMH) are magnetic field depressions in the solar wind found everywhere in the heliosphere and sometimes downstream of planetary bow shocks. LMH, with only very little rotation of the magnetic field B across the structure, are often considered as the evolutionary endpoint of mirror modes, thus retaining certain characteristics of their parent structure: embedded in a plasma with large temperature anisotropy, large plasma beta, anticorrelation between B and the plasma density. One question is how and under which conditions these large depressions may survive a shock crossing, as observations have recently shown that such a crossing is possible. In other words: what is the interaction between two nonlinear space plasma structures that both scale as the ion gyroradius? To answer this question, we present here the first hybrid simulations of the evolution of a LMH crossing the bow shock boundary of a medium-activity comet using the hybrid Particle-In-Cell (PIC) model Menura. We first create a LMH with mirror mode characteristics in the pristine solar wind and, then, convect it down toward a comet, through the shock, into the cometary magnetosheath. We study its morphology along its path, and how the magnetosheath is impacted locally and as a whole. This work also aims at preparing fundamental space plasma physics aspects of the upcoming multi-spacecraft Comet Interceptor mission.

How to cite: Henri, P., Simon Wedlund, C., Pucci, F., Behar, E., and Ballerini, G.: How do magnetic holes cross a bow shock? Results from the kinetic hybrid plasma model Menura, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6972, https://doi.org/10.5194/egusphere-egu23-6972, 2023.

The foreshock is a turbulent region in front of the quasi-parallel bow shock. The reflected particles from the bow shock and interaction with oncoming waves in the solar wind create it. The foreshock is usually located at the dawn side. However, the foreshock region is relocate to the nose of the bow shock and covers all the dayside magnetospheric system when IMF points to radial or anti-radial directions. This change creates many unusual phenomena in the magnetospheric system, such as the magnetopause expansion, and generates the foreshock transients, such as spontaneous Hot Flow Anomalies (sHFA). Previous studies revealed that foreshock transients are preferred to occur under a radial IMF condition, however, what is the reason for this preference is still unclear. Using THEMIS and MMS data, the analysis presents a statistical analysis to reveal the foreshock characteristics under the radial IMF to check the reasons for the preference of foreshock transients. The primary solar wind parameters in the foreshock and/or solar wind under these conditions are revealed. The ULF wave behavior is also taken account.

How to cite: Pi, G., Salohub, A., Xirogiannopoulou, N., Němeček, Z., and Šafránková, J.: A Statistical Study of Foreshock Environment under Radial IMF Conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8347, https://doi.org/10.5194/egusphere-egu23-8347, 2023.

The Earth’s magnetosheath is a dynamic region and its properties strongly depend on the angle between the bow shock normal and the solar wind magnetic field (θ_bn). If the shock is quasi-parallel (θ_bn < 45°), the magnetosheath is magnetically connected to the foreshock, causing strong fluctuations and structures propagating from upstream to downstream. A quasi-perpendicular shock (θ_bn > 45°) produces a less structured and more stationary magnetosheath characterized by compression and high ion temperature anisotropy. These distinct configurations make it possible to study how different plasma environments affect various processes such as turbulence, heating, and wave-particle interactions. Therefore, such studies require an accurate classification of the magnetosheath. This is not easily achieved, especially close to the magnetopause where the shock crossing for the plasma of interest cannot be observed.

Previously, Karlsson et al. (2021) used data from the Cluster mission to propose a promising classification method using local measurements of the magnetic field standard deviation, high-energy ion flux, and ion temperature anisotropy. In this work, we are building on this study and extending it to the Magnetospheric Multiscale (MMS) mission, having a different orbit than Cluster. We compare this local classification to θ_bn estimated from upstream conditions and well-known bow shock models, and discuss the advantages and disadvantages of the different methods.

Reference: Karlsson, T., Raptis, S., Trollvik, H., & Nilsson, H. (2021). Classifying the magnetosheath behind the quasi-parallel and quasi-perpendicular bow shock by local measurements. Journal of Geophysical Research: Space Physics, 126, e2021JA029269.

How to cite: Svenningsson, I., Yordanova, E., Khotyaintsev, Y. V., André, M., and Cozzani, G.: Classifying the magnetosheath using local measurements from MMS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8664, https://doi.org/10.5194/egusphere-egu23-8664, 2023.

Magnetic flux ropes with a wide range of scale sizes generally have high magnetic helicity, a magnetohydrodynamic (MHD) quantity that characterizes the knottedness of the field lines that can be used to identify flux rope structures. The identification and analysis of structures moving across boundaries such as the Earth's bow shock will give insight into how their properties change across this boundary as well as further our understanding of the interrelation between these structures. Recent spacecraft missions are returning higher time resolution data than before, allowing for more advanced studies of this phenomenon. Using high time-resolution data from the Magnetospheric Multiscale (MMS) mission and Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, we identify small-scale flux ropes using wavelet analysis and determine how they change across boundaries. Wavelet analysis of single-spacecraft data can produce better resolved time and spatial information that will complement other methods of flux rope identification. Wavelet transforms are performed across hours-long intervals, organized by the orbit configuration of the spacecraft. The resulting spectrograms are then searched to identify small-scale structures. A number of parameters, including duration, scale size, maximum magnetic field, and average plasma temperature of the flux rope intervals identified are also recorded and summarized. Comparing the values of magnetic field, plasma beta, and other parameters at the corresponding times and locations leads to interpretations for the flux rope events such as whether they are compressed, decelerated, or undergo any other changes as they evolve.

How to cite: Harvey, R. and Hu, Q.: Observational Analysis of Small-scale Structures in the Earth's Magnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9082, https://doi.org/10.5194/egusphere-egu23-9082, 2023.

Interplanetary shocks are some of the main drivers of geomagnetic storms. Before they can impact the geomagnetic environment, they propagate through the magnetosheath where their properties and geometry can be modified. What is the velocity of interplanetary shocks propagating through the magnetosheath? Previous numerical simulations and observations have given a wide range of apparently contradictory answers to this question, but they seem to all agree that interplanetary shocks generally slow down as they enter the magnetosheath: the interplanetary shocks’ velocity in the magnetosheath have been reported to be between 0.25 and 0.93 times their velocity in the solar wind. In this work, we offer two competing simple models to predict the propagation velocity of shocks through the magnetosheath. These models are applied to a list of shocks detected by currently operational spacecraft (e.g. Wind, MMS) as well as to results obtained from a hybrid PIC simulation. We show that our models both reconcile previous results and imply that interplanetary shocks could - in certain space weather-relevant situations - travel faster in the magnetosheath than they did in the solar wind. 

How to cite: Moissard, C., Bernal, A., Savoini, P., Fontaine, D., Modolo, R., David, V., and Michotte de Welle, B.: On the Speed of Interplanetary Shocks Propagating through the Magnetosheath, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9423, https://doi.org/10.5194/egusphere-egu23-9423, 2023.

Large scale solar wind (SW) structures called Coronal Mass Ejections (CMEs) and Stream Interaction Regions (SIRs) propagate through the interplanetary medium, where they might impact Earth and cause jet-like disturbances in the magnetosheath. Such jets are short scale structures characterized by an enhancement in dynamic pressure that propagate through the Earth’s magnetosheath (EMS) transporting mass, momentum and energy being able to affect and perturb the Earth’s magnetosphere.
Jets have been studied for 20 years, but how different SW conditions triggered by CMEs and SIRs affect jet production is a topic that has only recently begun to be studied. In this work we characterize jets observed by THEMIS during a CME and a SIR passage. We find clear differences in number and size between the jets associated with the CME regions arriving at the EMS as well as in comparison with the characteristics of jets associated with the SIR passage. Comparing WIND and THEMIS data we discuss how these differences are linked to the SW conditions in the context of a recent statistical study (Koller et al. 2022) and with different jet generation mechanisms.

How to cite: Preisser, L., Plaschke, F., Koller, F., Temmer, M., Roberts, O., and Vörös, Z.: On the production of magnetosheath jets during a CME and SIR passage: A case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9495, https://doi.org/10.5194/egusphere-egu23-9495, 2023.

Magnetosheath jets are dynamic pressure enhancements that are frequently observed downstream of the Earth's bow shock. Earthward propagating jets are significantly more likely to occur downstream of the quasi-parallel shock than the quasi-perpendicular shock. However, as the quasi-perpendicular geometry is the more common configuration at the Earth's bow shock, quasi-perpendicular jets can constitute a significant fraction of jets observed at Earth. Moreover, at other more quasi-perpendicular shock environments, such as at interplanetary shocks or the bow shocks of outer planets, they would be expected to form an even more significant portion of jets. We study the solar wind influence on jet formation in the quasi-parallel and quasi-perpendicular regimes by investigating jets in the Earth’s subsolar magnetosheath separately during low and high IMF cone angles. We find that during low IMF cone angles (downstream of the quasi-parallel shock) jet occurrence near the bow shock is not sensitive to other solar wind parameters. However, during high IMF cone angles (downstream of the quasi-perpendicular shock) jet occurrence is higher during low B, low n, high beta, and high M_A conditions. This suggests that quasi-perpendicular jet formation is related to shock dynamics amplified by higher beta and M_A. These observations from a wide range of solar wind parameters also allow us to make predictions of jet occurrence at other planetary systems.

How to cite: Vuorinen, L., Hietala, H., and LaMoury, A. T.: Solar wind parameters influencing magnetosheath jet formation: low and high IMF cone angle regimes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9960, https://doi.org/10.5194/egusphere-egu23-9960, 2023.

In this study, we present the analysis of steepened ultra-low frequency (ULF) waves in the foreshock region upstream of Mars’ bow shock observed by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft at Mars. A survey of MAVEN magnetic field and plasma measurements shows quasi-periodic gradual increases followed by a sharp decrease in the magnetic field magnitude (B_total). Higher frequency waves were also commonly, but not always, observed at the trailing edge of the large-amplitude increase in B_total. These observations are consistent with the signatures of shocklets observed in the solar wind region upstream of Earth’s and planetary bow shocks. Shocklets are believed to be formed as a result of the steepening of fast magnetosonic waves generated by reflected ions in the quasi-parallel foreshock region. We also performed the minimum variance analysis (MVA) and statistical analysis technique to determine the wave properties (e.g. polarization, wave propagation, amplitude and frequency) of the shocklets and higher frequency waves observed in its trailing edge. Our results showed that these shocklets are left-handed polarized in the spacecraft frame, with mean amplitude δB/B of ~3.5 and time separation between adjacent shocklet events of ~40s. We also analyzed measurements (ions and electrons) from MAVEN’s plasma instruments to investigate the energization process of the particles during the observations of shocklets. We will discuss the possible generation mechanisms for these steepened ultra-low frequency waves at Mars, and any implications for the martian plasma environment downstream of Mars’ bow shock. 

How to cite: Poh, G., Espley, J., Xu, S., Le, G., Romanelli, N., Halekas, J., DiBraccio, G., and Gruesbeck, J.: MAVEN Observations of Steepened Ultra-Low Frequency Waves in the Upstream Martian Foreshock Region, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10536, https://doi.org/10.5194/egusphere-egu23-10536, 2023.

Magnetic holes are coherent structures associated with a strong depression in the magnetic field amplitude. Such structures are ubiquitous in space plasmas and are observed in the solar wind, in planetary bow shocks and magnetosheaths, in the Earth's magnetotail and around comets. Magnetic holes may have very different sizes and properties. The largest ones have a size of hundreds of ion gyroradii while the smallest ones are sub-ion scale structures of the order of a few electron gyroradii. The drop in magnetic field amplitude associated with magnetic holes is often sustained by an increase in plasma density and enhanced ion and electron temperature anisotropies, with temperatures that are typically higher in the plane perpendicular to the local magnetic field. These properties seem to suggest that the generation of magnetic holes may result from the nonlinear evolution of mirror modes whose growth is fed by perpendicular temperature anisotropies and that are characterized by anticorrelated magnetic field and density perturbations. Some observational and numerical studies seem to support the idea of a scenario in which magnetic holes are generated by the mirror instability but in many cases this picture is not consistent with observations, especially in the case of sub-ion scale magnetic holes for which a number of possible generation mechanisms have been considered. Hence, the origin of magnetic holes is still controversial and under debate. 

Plasma turbulence is also known as a driver for the generation of coherent structures and may play a key role in the formation of magnetic holes, especially in the solar wind and in the Earth's magnetosheath that are in a turbulent state. Indeed, numerical simulations of plasma turbulence show that sub-ion scale magnetic holes can develop self-consistently out of small scale magnetic fluctuations that locally reduce the magnetic field amplitude and trap hot electrons. However, it is still unclear how such small scale fluctuations can emerge in a turbulent plasma where energy is typically injected at large scales. In this work, we study the formation of sub-ion scale magnetic holes by means of fully kinetic particle-in-cell simulations of plasma turbulence. We show that by injecting energy at scales relatively large with respect to ion scales, the turbulence naturally tends to generate sub-ion scale electron velocity shear layers associated with elongated magnetic field grooves. These elongated magnetic dips then become unstable and break up into sub-ion scale magnetic holes characterized by an intense azimuthal electron current and a strong perpendicular electron temperature anisotropy. We show that the properties of magnetic holes generated by this mechanism are consistent with satellite observations. Our results may provide a possible explanation of how magnetic holes develop in a realistic turbulent environment.

How to cite: Arrò, G., Pucci, F., Califano, F., and Lapenta, G.: Generation of sub-ion scale magnetic holes from electron shear flow instabilities in plasma turbulence, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10616, https://doi.org/10.5194/egusphere-egu23-10616, 2023.