NASA and ESA intend to conduct a Mars Sample Return (MSR) Campaign to return martian samples safely to Earth for scientific research, based on the highest priority recommendations of the international science community. Returned samples will allow scientists to utilize advanced sample processing and scientific instrumentation unavailable on robotic spacecraft.

The journey of scientifically selected samples starts with the context development and acquisition of the samples by the Mars 2020 Perseverance rover, continues with the transit through the flight elements of the MSR Program and retrieval on Earth for curation and analysis by the world’s scientific community. The samples collected by Mars 2020 to date already show scientific potential beyond the pre-launch expectations of the scientific community for the first sample return from Mars.

Based on an already signed NASA-ESA MSR Science and Sample Management Memorandum of Understanding, a Joint Science Management Plan (JSMP) has been developed to provide the framework and processes to ensure the scientific potential of the samples is preserved during return to Earth, on Earth, and for future generations, and that the science objectives of MSR can be met.

This talk will inform the science community about the key science management elements described in the JSMP.

How to cite: Kminek, G. and Meyer, M. A.: Mars Sample Return Science Management, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8764, https://doi.org/10.5194/egusphere-egu23-8764, 2023.

Chemical weathering is an important indicator of past climate and redox state [1-3]. On Mars, weathering profiles may have formed in basaltic sediments or volcanic ash that were altered by surface water and were subsequently buried and persevered in the geological record. Orbital remote sensing of the global Martian surface has detected dioctahedral clay minerals within Noachian layered sedimentary rocks, which are consistent with the precipitation-driven pedogenic weathering of mafic sediments [1]. Noachian sedimentary rocks with spectral signatures of subaerial weathering have been detected in thousands of locations across the surface of Mars [1,4].

In this study, orbital imagery, spectroscopy, topographic data and crater chronology are investigated to explore the geologic context, stratigraphy, and relative age of >200 weathering profiles across the Martian southern highlands [4]. The youngest might be Early Hesperian, although virtually all are older than 3.7 Ga. Weathering profiles exist across a wide range of elevations (>11 km), from −5 to 6 km, indicating they developed as a result of top-down, precipitation-driven chemical weathering and this was a global phenomenon. We discovered that almost all exposures show a similar, single stratigraphic relationship of Al/Si material overlying Fe/Mg clays, rather than several, interbedded mineralogy transitions. This points to either a single warming event or, more likely, a chemical resetting scenario in which the most recent event overprints the prior weathering pattern. The time necessary to develop a typical profile is estimated to be several million years, which corresponds to only a portion of the Noachian period. As a result, the broad estimated age span ~700–800 My appears incompatible with a single climate excursion. We consider that the presence of weathering profiles in many geologic units at a wide range of ages over a long period of geologic time and at a wide range of elevations, suggests a top-down, precipitation-driven chemical weathering was global in scope. Fe-mobility was a crucial component of chemically weathering, which happened geologically rapidly under anoxic conditions that might potentially warm the martian surface via reduced greenhouse gas. Collectively, these results indicate that multiple weathering episodes are driven by multiple reduced greenhouse conditions on ancient Mars.

[1] Carter et al. 2015, Icarus, 248, 373-382. [2] Bishop et al., 2018, Nature Astronomy, 2(3), 206-213. [3] Liu et al., 2021, Nature Astronomy,5(5), 503-509.[4] Ye & Michalski, Communication Earth & Environments, 3(1), 1-14.

How to cite: Ye, B. and Michalski, J.: Compositional stratigraphy on Mars as evidence of hundreds of millions of years of greenhouse conditions on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2249, https://doi.org/10.5194/egusphere-egu23-2249, 2023.

The Alpha Particle X-ray Spectrometers (APXS) onboard the Mars Exploration Rovers (MER) Spirit and Opportunity interrogated the bedrock, soil, and regolith at Gusev crater and Meridiani Planum, respectively. The APXS derives the composition of geologic materials through a combination of particle-induced X-ray emission (PIXE) and X-ray fluorescence (XRF) spectroscopy. Each measurement results in a histogram of energies with characteristic peak areas proportional to elemental concentrations. This spectrum reflects not only the composition of a target but also varies with experimental conditions (e.g., measurement duration, mission age, standoff, temperature), which must be accounted for to accurately quantify the elements present in a spectrum. Individual APXS measurements often provide sufficient counting statistics to resolve and quantify major, minor, and select trace elements (e.g., Ni, Zn, Br) while others (e.g., Ga, Ge) are more difficult to precisely quantify due to, in part, their typical low concentrations (e.g., sub-30 µg/g).

To combat the effect of statistical noise on trace element quantification, individual spectra are summed together to create a composite spectrum. We have assembled a database of target characteristics, such as target type (e.g., rock, soil), location, feature, target, formation, and degree of sample preparation (e.g., as-is, brushed, abraded), for each individual APXS spectrum. Spectra of targets with shared geological context and geochemical characteristics (e.g., ratio of Fe³⁺ to Fe_T) were summed to create meaningful combinations of individual spectra (i.e., composite spectrum). The composite spectra were fit with a simplified (i.e., Gaussian peaks with a linear background) nonlinear least squares fitting routine to identify promising composites for quantification with the fitting routine developed and utilized for the quantification of other elements within MER APXS spectra. Composite spectra were also assessed visually and quantitatively to confirm they were representative of trace element peaks within each of the individual spectra rather than outliers.

At both Meridiani Planum and Gusev crater, results indicate that the concentrations of Ga and Ge in outcrops are more than an order of magnitude higher than expected from meteoritic contribution alone. The ratios of Ga to Al and Ge to Si can also be used to infer the geologic history of a region due to their similar ionic radii and charges and therefore geochemical behavior. The Ga/Al molar ratio tends to be much more consistent at Meridiani Planum compared to that of Ge/Si, which shows more variation between formations. The divergence of the behaviors of Ge and Si could be explained by high temperature diagenetic fluids, as could the consistent behaviors of Ga and Al. We conclude that the elevated concentrations of trace elements such as Ga and Ge may be sourced in part from volcanic outgassing, and regional trends in the molar ratios of Ga/Al and Ge/Si are potentially due to high temperature diagenetic fluids.

How to cite: Knight, A., VanBommel, S., Gellert, R., Berger, J., Catalano, J., and Gross, J.: Trace Element Concentrations from the Mars Exploration Rover Alpha Particle X-Ray Spectrometers: Implications for the Geologic Histories of Meridiani Planum and Gusev Crater, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10444, https://doi.org/10.5194/egusphere-egu23-10444, 2023.

Mg sulfate (MGS) is one of the most common secondary minerals on Mars, with orbital detections spread across the planet and multiple occurrences and elevations within Gale crater. The mineralogy of MGS (including its crystallinity and hydration state) and its geologic setting can be used to place precise limits on aqueous conditions during formation and diagenesis. Both monohydrated Mg-sulfate and polyhydrated Mg-sulfate have been observed in Gale crater from orbit, and the MSL mission is now within the area where MGS-rich strata are identified from orbit, presenting an opportunity to examine these common martian minerals in situ. We map MGS-rich outcrops along the planned rover traverse route and similar stratigraphic range around all of Mt. Sharp. By comparing CRISM and HiRISE data in a restricted stratigraphic range, we identify small features of interest such as potential thin monohydrated MGS layers. As monohydrated MGS cannot have been exposed to liquid water or frost since formation, these are important outcrops for the rover to conduct contact science and gather high-resolution textural observations which can be used to test formation hypotheses.

How to cite: Sheppard, R., Rapin, W., Tu, V., Lim, L., Gabriel, T., Hughes, M., Fraeman, A., and Vaniman, D.: Updated orbital perspective of the Mt. Sharp upper sulfates in preparation for in situ exploration, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16728, https://doi.org/10.5194/egusphere-egu23-16728, 2023.

Manganese-rich phases have been detected in situ on Mars by the NASA Opportunity and Curiosity rovers, and in the martian meteorite NWA 7034 (and its pairs). Notably, instruments on Curiosity in Gale crater have detected Mn-rich materials in many geologic contexts, including fracture fills, coatings, nodules, and cements; this variety suggests a complex, long-term manganese cycle or cycles in the region. The origins of these materials is not well understood, but their existence points to strongly oxidizing aqueous environments in Mars’ distant past. On Earth today, manganese cycling is primarily mediated by microbes, making manganese minerals on Mars important targets for detailed study. On Earth, a significant geologic setting for Mn-rich materials is rock varnish, a dark, shiny coatings composed of Mn- and Fe-oxides and clays. Varnishes are ubiquitous in arid environments on Earth and have recently been shown to be produced and modified by microbial communities. Such varnishes have long been predicted for Mars (as an abiotic feature) but have not been observed until now. In Jezero crater, the SuperCam and Mastcam-Z instruments on the Perseverance rover have now documented a dark, shiny, Mn-rich coating on the rock Hogback Mountain, which is in the Hogwallow Flats region of Jezero Delta sediments. SuperCam laser-induced breakdown spectroscopy (LIBS) analyses of 30- and 150-shot depth profiles penetrated through a thin, Mn-rich layer with MnO as high as 30 wt% (avg 11 wt% MnO over all shots). Preliminary chemistry results suggest that Ni is positively correlated with Mn; this is consistent with a Mn-oxide mineral, which adsorb Ni, Co, and other metals when available. Acoustic data from the SuperCam microphone obtained concurrently with the LIBS depth profiles show that the high-Mn coating is relatively hard, and that material properties change beneath the coating at ~40 shots (~12 µm) depth, in good agreement with the LIBS chemistry data. SuperCam reflectance spectra (0.40-0.85 um, 1.3-2.6 µm) of the coating suggest contributions from phyllosilicates and likely Mn-bearing minerals, including but not limited to birnessite, [(Na,Ca)_0.5(Mn⁴⁺,Mn³⁺)₂O₄·1.5H₂O]), which is the most common Mn-oxide in terrestrial rock varnish. So far, Hogback Mountain is the only SuperCam target with such high Mn. However, Mastcam-Z multispectral observations suggest that similar Mn-rich coatings are present on rock surfaces throughout the area. On Earth, varnish formation (and Mn-mineral formation in general) is associated with organic materials. Notably, at the nearby Berry Hollow abrasion patch, high intensity fluorescence signals indicate that possible organics were found by the SHERLOC instrument. Further investigation of these signals and colocated Raman signals is ongoing. This observation of a varnish-like coating on Mars represents a new geologic context for Mn-bearing minerals on that planet that expands the range of environments known to produce these materials, and opens up new opportunities to answer questions about potential biosignatures on Mars.

How to cite: Lanza, N., Gasda, P., Ollila, A., Chide, B., Garczynski, B., Johnson, J., Fischer, W., Treiman, A., Williams, A., VanBommel, S., Knight, A., Hurowitz, J., Sharma, S., Kalucha, H., Conrad, P., Benzerara, K., Clave, E., Mandon, L., Wiens, R., and Maurice, S.: A varnish-like high-manganese rock coating in Jezero crater, Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10757, https://doi.org/10.5194/egusphere-egu23-10757, 2023.

The Perseverance rover landed on the floor of Jezero crater in February 2021. The initial set of images taken from the landing site of the residual butte Kodiak showed a deltaic architecture consistent with a paleolake, but at a level ~100 m lower than expected, suggestive of a closed lake system. After spending ~1 year studying the crater floor, the rover reached the front of the deltaic fan in April 2022. Here, we report observations of the facies, structure and composition of these sedimentary deposits using the SuperCam instrument. SuperCam can take images for texture analysis with the Remote Micro-Imager (RMI), visible and infrared reflectance (VISIR) spectra as well as Raman spectra for mineralogical analysis, and data from laser induced breakdown spectroscopy (LIBS) for chemical analysis. The rover investigated the basal strata of the delta along two traverses at the SE of the delta front. The transition between the crater floor and the delta is not well determined due to regolith and strongly degraded outcrops, and is currently under assessment. The ~20 m thick basal layers that are well-visible on orbital data consist of fine-grained sandstones and siltstones deposited in sub-horizontal planar beds with millimeter thick laminations. These deposits display a substantial alteration highlighted by the detection of both sulfates and phyllosilicates, with exception of local boulders of igneous texture lacking alteration. Texture and composition are both consistent with a quiet regime of deposition such as in lake deposits or distal delta slopes. These beds are considered of topmost importance for sample return and were cored in two locations. Pebbly sandstones and conglomerates with pebbles limited to a few centimeters are observed immediately above these strata. The texture is matrix-supported suggesting an emplacement through gravity sliding or turbidity flows below water rather than fluvial deposition. The composition is more variable than in underlying finer-grained beds and includes local carbonate detections. Uppermost deposits have not been reached by the rover yet, but have been analyzed remotely by RMI images, and VISIR for some of them. They consist of cross-bedded sandstones and conglomerates in all locations of the delta front. The diversity in texture of these deposits suggests a variability in depositional regimes including high-energy floods, either during the lacustrine phase, or subsequently. Boulders present within these layers are rounded suggesting a substantial abrasion by fluvial transport. These boulders are also interesting targets for sampling distant crustal rocks. The top of the delta will be analyzed and sampled along the traverse of the rover in 2023.

How to cite: Mangold, N., Caravaca, G., Dehouck, E., Beyssac, O., Beck, P., Clavé, E., Cousin, A., Dromart, G., Forni, O., Fouchet, T., Gasnault, O., Gupta, S., Le Mouélic, S., Mandon, L., Maurice, S., Meslin, P.-Y., Quantin-Nataf, C., Royer, C., and Wiens and SuperCam team, R.: Observations of the Perseverance rover at the Jezero crater delta front using the SuperCam instrument, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4896, https://doi.org/10.5194/egusphere-egu23-4896, 2023.

On February 18, 2021, NASA’s Mars 2020 Perseverance rover landed successfully on the floor of Jezero crater. Two geological and compositional units had previously been identified from orbital data analysis within the floor of Jezero crater [1,2]: a dark pyroxene-bearing floor unit and an olivine-bearing unit exposed in erosional windows [3]. During the 420 first sols of the mission, the rover has completed an in situ exploration campaign of these two units.

The SuperCam instrument contains a suite of techniques including passive spectroscopy in the 0.40-0.85 (VIS) and 1.3-2.6 microns (IR) wavelength ranges, Raman spectroscopy, Laser Induced Breakdown Spectroscopy (LIBS) and a camera providing high resolution context images [4,5]. Since the landing, SuperCam has acquired more than 3 thousands of observations.

From orbit the two geological units in the floor of Jezero have distinctive morphology and spectral signature. The crater floor unit called Cf-fr (Crater floor fractured rough) has a pyroxene signature [2] with no clear evidence of alteration.  The unit is laying on the top of the olivine rich unit. The interpretations varied from lacustrine deposits to volcanic deposits. The underlying unit seems to be part of the regional olivine-rich deposits with parts altered into carbonates and clays [1,6]. Interestingly, this regional olivine rich unit has a unique spectral signature on Mars, an effect of either grain size or composition [7]. Many hypotheses have been suggested: Isidis impact related ejectas layer [8], pyroclastic deposits [i.e. 6] or clastics deposits [9].   

In situ, we discovered that the Cf-fr, composed of different sub-units is not layered, composed of grainy rocks, dominated by plagioclase and Fe-rich pyroxenes [10] with a restricted but pervasive multistage [10]. From in situ data, Maaz is interpreted lava flows [11, 12] emplaced before the last lacustrine activity associated with the main western delta fan. Below the cf-fr, Seitah occurs as layered Mg-olivine rich rocks generally flat but slightly plunging below Maaz on the edges. The rocks are dominated by mm grains of pristine Olivine and some pyroxenes [10, 13, 14] .  The various spectroscopic methods detected alteration phases such as Mg- phyllosilicate and Mg Carbonates. [15, 16]. The rock texture and petrology of Seitah were interpreted as an olivine cumulate with limited alteration.

Lessons learned from this in situ campaign will be presented such as how accurate are the orbital spectral analyses, the morphological analysis and how to transfer the results of Jezero to the other places on Mars investigate by orbital data only.  

References :  [1] Horgan et al., 2020 [2] Goudge et al., 2015  [3] Tarnas, et al., 2021. [4] Wiens, et al., 2021. ; [5]  Maurice et al., , 2021 ; [6] Mandon et al., 2020.  [7] Ody et al.,2013   [8] Mustard et al., 2006 [9] Rogers et al., 2018, [10] Wiens et al., 2021 ; [11] Udry et al., 2022, [12] Horgan et al., 2022, [13] Liu et al., 2022, [14] ; Beyssac et al., 2023 [15] Mandon et al., 2022 [16] Clave et  al., 2022.

How to cite: Quantin-Nataf, C., Beyssac, O., Udry, A., Mandon, L., Clave, E., Benzerara, K., Dehouck, E., Poulet, F., Beck, P., LeMouelic, S., Mangold, N., Cousin, A., Meslin, P. Y., Forni, O., Gasnault, O., Wiens, R., and Maurice, S.: Comparison of orbital and Supercam in situ investigation of the floor Units of Jezero crater, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14114, https://doi.org/10.5194/egusphere-egu23-14114, 2023.

The NASA Perseverance rover has encountered numerous instances of purplish colored surficial material on rocks and pebbles throughout its traverse across the Jezero crater floor and the delta front. These enigmatic materials are visible on many different rock types and can vary in apparent thickness, from being very thin (microns) to several mm thick, and potentially forming in more than one layer. On Earth, such thin layers may form from a variety of processes, e.g., as coatings deposited on rock surfaces, exposed fracture fills, and/or alteration rinds/case hardening. The purple materials observed at Jezero typically unconformably overlie eroded natural rock surfaces, suggesting these features are possibly surface coatings of externally derived material. On Earth, coatings arise due to interactions between rock surfaces and the atmosphere, liquid water, and life. As such, they represent important targets for study on Mars.

Using Laser-Induced Breakdown Spectroscopy (LIBS) and a microphone, SuperCam is able to analyze these coatings for chemical composition (LIBS) and material properties (recording the LIBS acoustic signal). By interrogating the same location with the LIBS laser multiple times, changes in composition and material properties with shot (depth) may be observed if the layer is thin enough. SuperCam has made 125-150 laser shot depth profiles on several of these coated rocks, at 4-5 locations on each. For each raster, we attempt to have at least one point on an uncoated area to compare with the coated surface profile. Whenever possible, SuperCam analyses of coatings were made at locations adjacent to a rover-made abrasion patch, where the upper ~mm is abraded off to expose the underlying rock. Here we focus on comparing compositions of depth profiles on purple coatings that are directly adjacent to abrasion patches; these targets are Cordoeil (sol 268), near the abrasion patch Dourbes, Chokecherry (sol 378) which is near the Alfalfa abrasion patch, and Pile_Bay (sol 582) located by the Novarupta patch. Coating compositions from these targets roughly matches that of the fine martian dust (e.g., Lasue et al., 2018, doi.org/10.1029/2018GL079210), potentially indicating a link between the two. Airfall dust is an important contributor to rock coating formation on Earth and may likewise play a role for coating formation on Mars.       

How to cite: Ollila, A., Chide, B., Lanza, N., Garczynski, B., Schmidt, M., Gasda, P., Forni, O., Cousin, A., Dehouck, E., Wiens, R., Maurice, S., Nachon, M., Johnson, J., and Clegg, S. and the SuperCam Team: Analysis of Purple Coatings by the SuperCam Instrument on the Perseverance Rover in Jezero Crater, Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10794, https://doi.org/10.5194/egusphere-egu23-10794, 2023.

The RIMFAX ground penetrating radar instrument on board the Mars 2020 Perseverance Rover has been continuously sounding the subsurface along
the Rover traverse. In the data of the first 379 mission days on the Jezero Crater Floor we are able to identify hyperbolic patterns, likely caused by buried scatterers such as boulders or cavities in the upper 5 m of the subsurface. We present the first detailed estimates of radar wave propagation velocity by matching theoretical traveltime hyperbolas to the patterns generated by scatterers. The average dielectric permittivities are derived from these velocities and, consequently, the bulk rock densities for material above the scattering source. Simultaneously, we investigate the surface reflectivity to retrieve permittivity and density of the uppermost centimeter. Finally, we assess the radar attenuation by a constant-Q approach.
The results are consistent with a solid rock, mafic interpretation of the Jezero Crater subsurface. The talk is based on the respective two most recent publications as well as work in progress.

How to cite: Casademont, T. M., Eide, S., Shoemaker, E., Berger, T., Russell, P., and Hamran, S.-E.: Rock Properties of Shallow Martian Subsurface with the RIMFAX Ground Penetrating Radar, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15500, https://doi.org/10.5194/egusphere-egu23-15500, 2023.

SHARAD (Shallow Radar) and MARSIS (Mars advanced Radar for subsurface and ionosphere sounding) are two low frequency sounder radars in orbit around Mars whose aim is to assess the distribution of on-ground and buried water, to provide the material composing its crust and to study its topography at global scale. The estimation of dielectric properties using radar data, can be pursued by means of different methods, including a parametric data inversion approach. Our method provides for the estimation of surface permittivity and loss tangent by exploiting the ratio between the return powers from the surface and the subsurface at different frequencies. As the roughness of the surface as well as the subsurface, affects  the returned power, inversion techniques are often applied  on moderately flat surfaces, where the power loss due to roughness can be considered negligible.

In this work we present an approach for the estimation of surface roughness properties and power loss compensation via waveform fitting, whose shape is modified in relation to the  characteristics of the surface impinged by the emitted electromagnetic wave. Such fitting procedure exploits a large-scale roughness model for the power return obtained under the Kirchhoff approximation hypotheses and comprising both the coherent and the non-coherent components of the scattered field. Our method allows to estimate the roughness regime of the selected area in terms of height standard deviation and root mean squared slope and therefore to compensate for  power losses in relation with the estimated parameters.

The performances of the fitting procedure are tested using a ray-tracing simulator of the range-compressed SHARAD and MARSIS received signal. As a fist step we applied the analysis on isotropic gaussian surfaces with different roughness characteristics showing the possibility to recover the power lost due to roughness effects. Moreover, the analysis will be performed on MOLA simulated products to represent MARS surface and finally, will be applied to SHARAD real data acquired over the volcanic region of Elysium Planitia.

How to cite: Gambacorta, L., Mastrogiuseppe, M., and Seu, R.: Radar Sounding Waveform Fitting for Roughness parameters estimation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4218, https://doi.org/10.5194/egusphere-egu23-4218, 2023.

Recurring Slope Lineae (hereinafter RSL) are seasonal dark flows on Mars steep slopes. These movements of several meters long appear and grow downwards (more or less incrementally) and fade (partially or totally) more or less progressively. After investigating wet origins, dry processes involving dust are favoured (e.g., dust-removed features, dark sand movements, …) but are not yet precisely understood. One of the main common features between RSL and dust is seasonality, for example major formations are observed during the dust storm season at all latitudes. A specific RSL seasonality composed of three pulses of RSL apparition or lengthening has been found by Stillman et al. (2018) at Hale crater (323.48°E, 35.68°S). Here we assess whether this RSL timing could be related to the three pulses of the dust cycle. So, we reanalyse the observations of Hale to characterise the RSL activity with a dust removal/deposition point of view, trying to constrain the formation triggers (dust deposition, winds, …) and formation scenario for RSL.

We analyse consecutive high-resolution images (>0.25 m/pixel) of two Hale areas, taken by HiRISE onboard Mars Reconnaissance Orbiter, for Martian years 31, 32, and 33. We divided the characterisation into two parts: periods of apparition or lengthening of RSL-like features (i.e., when the extent of dark surfaces increases) and periods of RSL fading or disappearing (i.e., when the contrast between dark surfaces and adjacent bright surfaces decreases). In the framework of the “dust-removed” hypothesis for RSL, these two periods correspond respectively to dust removal and deposition periods. Each of those has three levels of intensity: low, intermediate and high. Then, we compare this RSL activity timeline to atmospheric dust optical depth variations over Hale.

With this new characterisation, we overall find again the three southern hemisphere spring/summer pulses and we also have identified an RSL formation event occurring near winter solstice (not already noticed). Then, we notice that there are dust depositions before each pulse, which correspond to a long decrease of atmospheric dust optical depth (1^st pulse) or two local peaks (2^nd and 3^rd pulse). This may imply that dust deposition at RSL locations can occur as both progressive fallout or rapid transport associated with storms. This also implies that a certain surface dust deposition seems to be necessary to have a significant level of RSL formation, but it does not seem to be always sufficient to trigger RSL formation. Indeed, local increase in atmospheric dust, which could be related to increased wind activity, seems to be required (1^stpulse) or seems to favour RSL formation (3^rd pulse).

Thus, we can propose an RSL formation scenario consistent with these observations: if there is enough surface dust deposition, a dry avalanche-type formation can be observed (possibly initiated by winds); with less dust deposition or slope unfavourable conditions (not allowing avalanche) the RSL lengthen downward more incrementally (as for the 3^rd pulse) under the action of winds. This proposed scenario elaborated using Hale observational constraints will be tested, improved, and confirmed with similar analyses performed at other RSL sites.

How to cite: Leseigneur, Y. and Vincendon, M.: Study of Recurring Slope Lineae Activity in Hale Crater: Wind and Dust Deposition Triggers., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14614, https://doi.org/10.5194/egusphere-egu23-14614, 2023.

Aeolian activity, the movement of sand and dust by the wind, is common on Earth and has been observed on other planets [1]. Under the current climatic conditions on Mars, aeolian activity is the primary process of surface modification driven by winds, dust storms and wind vortices. Landed and orbiting cameras show that widespread aeolian activity occurs despite low measured and modelled winds, challenging Earth-based theories [2, 3]. Dust particles enter into long-term suspension forming global dust storms which drastically alter the Martian atmospheric dynamics and present hazards to robotic and human missions.

Several models have been proposed on the long-standing conundrum of sediment transport on Mars, however, none of these have been verified on the planet. The outstanding question of what wind shear velocities mobilize sediments on Mars has remained elusive despite multiple spacecrafts carrying wind sensors and studying aeolian activity on finer spatial and temporal scales than can be achieved in orbit. Quantitative examination of aeolian activity under natural Martian surface conditions is imperative in validating transport models.

The InSight lander has provided a unique opportunity for monitoring simultaneous coverage of aeolian activity on Mars by combining, for the first time, imaging with atmospheric, seismic and magnetic measurements. Previous studies spanned over just half of the first Martian year, from the end of northern winter to midsummer, and observed minor aeolian activity limited to sporadic grain motion and dust devil tracks [4, 5].

In this study, we extend observations of aeolian activity for two Martian years, allowing us to infer the seasonal evolution at the landing site. We report a series of remarkable daytime vortex-induced events with pressure excursions up to 10 Pa, including an investigation of the burst in daytime vortices and emergence of nighttime vortices in northern autumn. Despite our observations reinforcing the quiescent aeolian surface environment at InSight, we observe further evidence and constrain timings of surface track formation, saltation, dust lifting and surface creep of coarser particles both on the surface of Mars and lander elements. Such an investigation was previously impossible due to power constraints allowing only intermittent meteorological measurements in the second year and wind-sensor saturation from energetic close vortex encounters that cause surface changes. Here, we derive estimates of vortex-induced peak wind speeds responsible for grain motion based on strong correlations from the excitation of high-frequency lander resonances sensitive to wind forcing measured continuously by the seismometers [6]. This wealth of data allows us to obtain a unique catalogue of complete wind-induced surface activity at InSight over two Martian years. Our findings provide an insight into the long-standing paradox of aeolian transportation on Mars by quantifying the environmental variables responsible for sand motion which help constrain current threshold and transport models.

[1] Hayes (2018) Sci. [2] Kok et al. (2012) RPP [3] Newman et al. (2022) Auth. [4] Charalambous et al. (2021) JGR 126(6) e2020JE006538 [5] Baker et al., (2021) JGR [6] Charalambous et al. (2021) JGR 126(4) e2020JE006514.

How to cite: Charalambous, C., Golombek, M., Pike, T., Lemmon, M., Spiga, A., Newman, C., Ansan, V., Baker, M., Banks, M., Lorenz, R., Stott, A., and Viudez-Moreiras, D.: The Aeolian Activity at InSight Over Two Martian Years, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9921, https://doi.org/10.5194/egusphere-egu23-9921, 2023.

After one year of surface operations at Jezero, the MEDA meteorological sensors have captured the signals produced by the close approach of hundreds of vortices and dust devils over different seasons and terrains. Here we update findings on the vortex and Dust Devils published in Hueso et al. (JGR: Planets, 2023). That work analyzed MEDA data from spring to early autumn identifying vortices as pressure drops and later characterizing them from the ensemble of MEDA measurements. In this updated analysis we show that, in winter, declining surface temperatures and smaller vertical gradients result in a wane of vortex activity. This decreased activity affects more the frequency of intense vortices (Δp >1.5 Pa) without showing a stiff decay in the total number of vortices (Δp>0.5 Pa). In this contribution we concentrate on the specific aspects of the thermodynamics of the vortices from temperature measurements obtained by MEDA that characterize the vertical thermal gradient at the time of the vortex passage. In addition, when vortices approach the rover closely in a favorable geometry (coming from the front of the vortex) we measure the increased temperatures inside the vortex. We also explore the increased nighttime vortex activity found on some sols, when pressure drops equivalent to those created by daytime vortices appear in the early morning before sunrise, with clusters of nighttime activity in winter and early spring.

How to cite: Hueso, R., Newman, C., del Río-Gaztelurrutia, T., Aiser, M., Sánchez-Lavega, A., Toledo, D., Lemmon, M., Martínez, G., Lorenz, R., de la Torre-Juarez, M., Rodríguez-Manfredi, J. A., Pla-García, J., Murdoch, N., and Chide, B.: Vortices and Dust Devils at Jezero crater after one year of measurements with MEDA on Mars 2020, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6062, https://doi.org/10.5194/egusphere-egu23-6062, 2023.

Air temperature, ground temperature, pressure, and wind speed and direction data obtained from the APSS (Auxiliary Payload Sensor Suite) and HP3 radiometer (RAD) onboard the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander are compared to data from the Mars Regional Atmospheric Modeling System. A full diurnal cycle at four different seasons (Ls 0º, 90º, 180º and 270º) is investigated at the lander location at 4.5° N 135.6° E in Elysium Planitia on Mars (Figure shows comparison results for Ls 180º). This work extends the atmospheric observations perform by [1]. Model results are shown to be in good agreement with observations. The good agreement provides justification for utilizing the model results to investigate the broader meteorological environment of Elysium Planitia in a companion paper. The observed air temperature, pressure and winds are taken at ∼1m above ground, while MRAMS provides those values at the lowest atmospheric model level of ∼14 m. As expected, the MRAMS air temperature values at this height tend to be cooler than the observed in the morning and early afternoon, and then tend to be warmer in the late afternoon and through the night. Also, the difference in height should not have a large impact on wind direction, but modeled wind speeds at ∼14 m are faster than the observed at 1.5 m due to frictional effects. Small discrepancies in ground temperatures could be attribute to a different initialization of thermal inertia, dust and clouds in the model when compared with the data. The diurnal pressure amplitude at Elysium Planitia varies from 2.52% to 4.5% depending on the season. The total amplitude is then considerably smaller compared to Gale crater (up to ∼13%, [2]). [3] attributed the amplification at Gale due to a mesoscale hydrostatic adjustment process in regions of topographic slopes. We also use a Computational Fluid Dynamics (CFD) to study the mechanical disturb of the wind directions due to other instruments onboard the lander and it effect into the wind directions discrepancy between modeling and observations [4]. For low wind speeds (~3.4 m/s), there is an important mechanical contamination in the 330º-30º wind directions range for FM1 and in the 210-330º range for FM2 (Figure bottom left), mostly during nighttime.                                                         

Figure 1. Observed and modeled diurnal air temperature, ground temperature, pressure, wind speed and wind direction signal at Ls 180. MRAMS are the black dots. InSight data taken within a few sols of the Ls 180 are shown in different colors, which each color representing data from a single sol. CFD results with the mechanical disturb (from the higher value -0- to the lower value -1.2-) of the wind directions due to other instruments onboard the lander for low wind speeds (~3.4 m/s) are shown in the bottom left.

How to cite: Ruíz-Pérez, M., Pla-García, J., Spiga, A., C. R. Rafkin, S., Mueller, N., Newman, C., Navarro, S., Torres, J., Lepinette, A., Banfield, D., Mora, L., and Rodríguez-Manfredi, J. A.: The meteorology of Elysium Planitia (Mars) as determined from InSight observations and numerical modeling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-475, https://doi.org/10.5194/egusphere-egu23-475, 2023.

Pressure, ground temperature, air temperature close to the surface and at 40 m height, and wind speed and direction data obtained from MEDA [Rodriguez-Manfredi et al. 2021] onboard Perseverance rover are compared to data from MRAMS [Rafkin and Michaels 2019]. A full diurnal cycle at twelve different times of a complete martian year (Ls 30º, 60º, 90º, 105º, 160º, 180º, 210º, 240º, 270º, 300º, 330º and 360º) are investigated at the rover location at 18.44°N; 77.45°E inside Jezero crater on Mars. Figure shows comparison results for Ls 90º. This work extends the predictions shown in [Pla-García et al. 2020, Newman et al. 2021]. A diurnal structure variation of the pressure throughout the year is shown both in modeling and observations. The diurnal pressure amplitude is generally well matched in the model but the phase of the diurnal tide is shifted about ~90 min. The general shape of the diurnal cycle of surface temperature are similar between the two datasets. MRAMS surface properties are interpolated from data sets obtained from TES thermal inertia (nighttime) and albedo, with insufficient resolution to capture the known variation of thermal inertia in Jezero crater and the misestimating the diurnal amplitude. The lowest MRAMS thermodynamic level is ∼14 m above the ground, so modeled air temperatures tend to be cooler than MEDA observations at ∼1.5 m above the surface in the morning and early afternoon, and then tend to be warmer in the late afternoon and through the night. This is a direct result of the steep afternoon superadiabatic lapse rate and a strong nocturnal inversion [Schofield et al. 1997]. There is a good match in wind directions between MRAMS and MEDA, but MRAMS wind speeds are generally higher than those observed with MEDA, especially between 23:00 and dawn. The difference in height should not have a large impact on wind direction but can contribute to the wind speed differences due to frictional effects with the surface. Those wind speed differences are indeed bigger during nighttime, where MRAMS winds between 01:00 and sunrise could be so strong because the downslope winds penetrate a little bit too far into the crater for that time of sol when compared with other modeling predictions [Newman et al. 2021]. It is also noticeable that the wind speeds are systematically extremely low after sunset both in MRAMS and MEDA, following the collapse of daytime convection [Banfield et al. 2020], but then at 20:00 the wind speeds start to increase again both in modeling and observations. Although there are some periods with differences, generally there is a good agreement between MRAMS results and MEDA observations, and this agreement provides justification for utilizing the model results to investigate the broader meteorological environment of the Jezero crater region in a companion paper

Figure. Observed and modeled diurnal air temperature, ground temperature, pressure, wind speed and wind direction signal at Ls 90. MRAMS are the black dots. MEDA data taken within a few sols of the Ls 90 are shown in blue.

How to cite: Pla-Garcia, J., Newman, C., Munguira, A., Sánchez-Lavega, A., Hueso, R., del Río Gaztelurrutia, T., and Rodríguez-Manfredi, J. A. and the Mars 2020 MEDA team: The meteorology of Jezero crater (Mars) as determined from MEDA observations and numerical modeling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-735, https://doi.org/10.5194/egusphere-egu23-735, 2023.

The Thermal Infrared Sensor (TIRS; Sebastián et al., 2021; Martínez et al., 2023) is one of the six sensor packages of the Mars Environmental Dynamics Analyzer (MEDA; Rodríguez-Manfredi et al., 2021), which in turn is one of the seven science instruments on board Perseverance. Here we show a summary of TIRS scientific highlights during the first Martian year of operations. In particular, TIRS is providing the first in situ determination of the surface radiative budget, direct determination of broadband albedo and thermal inertia (Martínez et al., 2023; Savijärvi et al., 2022), and around-the-clock determination of aerosol opacities (Smith et al., 2023). In addition, TIRS is providing ground-truth to orbital retrievals of thermal inertia and albedo, as well as geophysical characterization of the uppermost surface of the regolith during Phobos and Deimos eclipses. In synergy with other instruments, TIRS is being used to determine vertical profiles of temperature (Munguira et al., 2023), to detect dust lifting from sudden changes in albedo (Vicente-Retortillo et al., 2023), and to assess changes in the water content of the Martian soil (Hausrath et al., 2023), including the potential formation of frost.

TIRS observations are critical to achieve MEDA’s first programmatic objective (validate global atmospheric models by measuring the radiative surface budget in preparation for future human exploration). Also, TIRS observations are important in support of flights of Ingenuity and therefore for the design and operations of future drones. 

References:

Hausrath, E. M. et al. (2023), The SuperCam team and the Regolith working group, An Examination of Soil Crusts on the Floor of Jezero crater, Mars, Journal of Geophysical Research: Planets (accepted).

Martínez, G. M. et al. (2023), Surface Energy Budget, Albedo and Thermal Inertia at Jezero Crater, Mars, as Observed from the Mars 2020 MEDA Instrument, Journal of Geophysical Research: Planets (accepted).

Munguira, A. et al. (2023), Near Surface Atmospheric Temperatures at Jezero from Mars 2020 MEDA measurements, Journal of Geophysical Research: Planets (under review).

Rodriguez-Manfredi, J.A. et al. (2021), The Mars Environmental Dynamics Analyzer, MEDA. A suite of environmental sensors for the Mars 2020 mission, Spa. Sci. Rev., 217(3), 1-86.

Savijärvi, H. I. et al. (2022), Surface energy fluxes and temperatures at Jezero crater, Mars, Journal of Geophysical Research: Planets: e2022JE007438.

Sebastián, E. et al. (2021), Thermal calibration of the MEDA-TIRS radiometer onboard NASA's Perseverance rover, Acta Astronautica, 182,144-159.

Smith, M. D. et al. (2023), Diurnal and Seasonal Variations of Aerosol Optical Depth Observed by MEDA/TIRS at Jezero Crater, Mars, Journal of Geophysical Research: Planets (accepted).

Vicente-Retortillo, A. et al. (2023), Dust Lifting Through Changes in Albedo at Jezero Crater, Mars, Journal of Geophysical Research: Planets (under review).

How to cite: Martinez, G., Sebastian, E., Smith, M., Savijärvi, H., Gillespie, H., Vicente-Retortillo, A., Munguira, A., Hueso, R., Toledo, D., Tamppari, L., Newman, C., Sanchez-Lavega, A., Lemmon, M., Apestigue, V., Arruego, I., Fischer, E., Pla-Garcia, J., Mora-Sotomayor, L., de la Torre Juarez, M., and Rodriguez-Manfredi, J. A.: One Martian Year of MEDA/TIRS observations at the Mars 2020 landing site, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10117, https://doi.org/10.5194/egusphere-egu23-10117, 2023.

Clouds on Mars are primary elements for understanding the past and present climate of the planet. Cloud particles can affect the energy balance of the planet, and so the atmospheric dynamic, as well as influence the vertical distribution of dust particles through dust scavenging. The dust scavenging by clouds has critical consequences in the water cycle of the planet; e.g. regions in the atmosphere with insufficient quantity of dust particles (or condensation nuclei) can inhibit the formation of H₂O clouds and thus lead to the presence of water vapor in excess of saturation. The study of these interactions requires observations whose analysis allows us to infer simultaneously the properties of both the clouds and dust. To address these observations, the Radiation and Dust Sensor (RDS) is part of the Mars Environmental Dynamics Analyzer (MEDA) payload onboard of the Mars 2020 rover Perseverance.

In this work we analysed the RDS observations made during twilight in the period Ls 39^◦-262^◦ to characterize the clouds above ∼ 30 km over the Perseverance rover site. From the ratio between the irradiance measured at zenith at 450 nm and 750 nm, we inferred that from Ls= 39^◦ to 150^◦ (referred as the cloudy period), water ice is the main constituent of the detected high-altitude aerosol layers. For Ls 150^◦-262^◦ dust is the main aerosol present. A total of 161 twilights were analysed in the cloudy period with a radiative transfer code in spherical geometry. Among other results we found: i) signatures of clouds or hazes on the RDS signals in the 58 % of the twilights; ii) most of the clouds were at altitudes between 40 km and 50 km and with particle sizes between 0.6 μm and 2 μm (in effective radius); iii) the cloud activity at sunrise is slightly higher that at sunset (65 % against 52 %), likely due to the differences in temperature; iv) the cloudiest time in Perseverance site and with the greatest cloud opacities is in Ls 120^◦-150^◦; and v) a notable decrease in the cloud activity around the aphelion (Ls ∼ 70^◦), along with lower cloud altitudes and opacities. The drop in cloud activity around Ls ∼ 70^◦ indicates lower concentrations of water vapor or cloud nuclei (dust) around this period in the Martian mesosphere. In this presentation, we will discuss the implications of our results on the water cycle of the planet.

How to cite: Toledo, D., Gomez, L., Apéstigue, V., Arruego, I., Lemmon, M., Smith, M., Patel, P., Munguira, A., Sanchez-Lavega, A., Yela, M., Viudez-Moreiras, D., Martínez, G., Vicente-Retortillo, A., Newman, C., de la Torre Juarez, M., and Rodríguez-Manfredi, J. A.: Mesospheric clouds in Jezero as observed by MEDA Radiation and Dust Sensor (RDS) at twilight, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11004, https://doi.org/10.5194/egusphere-egu23-11004, 2023.

Pressure measurements by the MEDA sensor on board Perseverance Rover show oscillations in a wide range of temporal scales, from the seasonal evolution of average pressure to rapid fluctuations on the scale of a few seconds. In this work, we profit from an entire Martian Year of pressure measurements to analyse the seasonal and daily evolution of rapid fluctuations, a signature of atmospheric turbulence.  We find that during the full Martian year, fluctuations are enhanced at convective hours of the day, but the intensity of fluctuations is modulated through the seasons. At nighttime, the first half of the Martian years is characterized by an almost complete absence of fluctuations with an especially calm period in the early morning, while bursts of fluctuation become common in the dusty season. We also analyse the change of the daily pattern induced by regional dust storms at Jezero. We study the power spectra of the fluctuations to try to infer information about different turbulent regimes at the surface layer and their dependence on local time and season. Finally, we explore possible correlations with the dust load of the atmosphere and the temperature gradients, and we look at the origin of nighttime bursts of turbulence.

How to cite: del Río Gaztelurrutia, T., Sanchez-Lavega, A., Hueso, R., Munguira, A., Lemmon, M. T., Smith, M. D., Martinez, G., Pla-Garcia, J., Newman, C., Viudez, D., de la Torre-Juarez, M., and Rodriguez-Manfredi, J. A.: Daily and Seasonal Behaviour of Fast Pressure Fluctuations at Jezero Crater, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7173, https://doi.org/10.5194/egusphere-egu23-7173, 2023.

As a potential biomarker, Martian methane has attracted attention through several reports of its detection over the last 20 years. However, the very existence of this gas has been continuously questioned, in particular because the observed lifetime should be several orders of magnitude shorter than the 300 years predicted by photochemical models. Although several fast removal processes have been hypothesized to explain the observations, none of them has met a large consensus.

It is in this context that the ESA-Roscomos ExoMars Trace Gas Orbiter (TGO) mission started its science operations in April 2018. ACS and NOMAD, two instruments onboard the TGO, have been collecting hundreds of highly sensitive measurements in solar occultation. No methane has been detected so far and an upper limit of 0.02 ppbv has been derived. The implications of this result on the methane problem on Mars will be addressed in this work.

This upper limit is a strong constraint on the background level and, in turn, on the potential emission scenarios making the reported methane detections consistent with the TGO results. While several model studies aimed at identifying them, we will here adopt a probabilistic approach to the problem in order to question the plausibility of those detections and estimate the lifetime required to make them plausible from a probabilistic standpoint.

How to cite: Viscardy, S., Robert, S., Erwin, J. T., Thomas, I. R., Daerden, F., Trompet, L., Willame, Y., and Vandaele, A. C.: On the plausibility of methane detections on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15704, https://doi.org/10.5194/egusphere-egu23-15704, 2023.

The Martian planetary boundary layer (PBL) drives the surface-atmosphere exchange processes such as the Martian dust cycle, which leads to strong atmospheric variations from diurnal to seasonal and inter-annual time scales [1]. The amount of dust lifted into the atmosphere and the vertical winds that balance the gravitational settling for the aerosols are affected by the turbulent mixing within the boundary layer. Several studies focused on the dynamics of the Martian PBL during daytime conditions [2,3]. During daytime conditions, the strong buoyancy caused by the vertical thermal gradient can generate turbulent mixing and initiate turbulence. On the other hand, the nighttime boundary layer is suggested to form under very weak turbulent mixing conditions. However, recent observations by the InSight lander showed unexpected turbulent signatures during nighttime conditions [4]. Nevertheless, lacking the observational datasets revealing the vertical variation of temperature and winds within the first kilometer of the Martian atmosphere, we do not fully understand the dynamics of the Martian boundary layer. To complement the limited observations on the Martian boundary-layer meteorology, high-resolution limited area models, so called large-eddy simulations (LES), are used. Here, we use the LES module of MarsWRF [3,5] to investigate the time and length scales of nighttime turbulence and possible large-scale atmospheric phenomena that can affect the near-surface nighttime meteorology. We present possible implications related to the Martian dust cycle.

[1] Senel, C.B., Temel, O., Lee, C., Newman, C.E., Mischna, M.A., Muñoz‐Esparza, D., Sert, H. and Karatekin, Ö., 2021. Interannual, Seasonal and Regional Variations in the Martian Convective Boundary Layer Derived From GCM Simulations With a Semi‐Interactive Dust Transport Model. Journal of Geophysical Research: Planets, 126(10), p.e2021JE006965.
[2] Spiga, A., Forget, F., Lewis, S.R. and Hinson, D.P., 2010. Structure and dynamics of the convective boundary layer on Mars as inferred from large‐eddy simulations and remote‐sensing measurements. Quarterly Journal of the Royal Meteorological Society: A journal of the atmospheric sciences, applied meteorology and physical oceanography, 136(647), pp.414-428.
[3] Temel, O., Senel, C.B., Porchetta, S., Muñoz-Esparza, D., Mischna, M.A., Van Hoolst, T., van Beeck, J. and Karatekin, Ö., 2021. Large eddy simulations of the Martian convective boundary layer: towards developing a new planetary boundary layer scheme. Atmospheric Research, 250, p.105381.
[4] Temel, O., Senel, C.B., Spiga, A., Murdoch, N., Banfield, D. and Karatekin, O., 2022. Spectral analysis of the Martian atmospheric turbulence: InSight observations. Geophysical Research Letters, 49(15), p.e2022GL099388.
[5] Wu, Z., Richardson, M.I., Zhang, X., Cui, J., Heavens, N.G., Lee, C., Li, T., Lian, Y., Newman, C.E., Soto, A. and Temel, O., 2021. Large eddy simulations of the dusty Martian convective boundary layer with MarsWRF. Journal of Geophysical Research: Planets, 126(9), p.e2020JE006752.

How to cite: Temel, O., Senel, C. B., and Karatekin, O.: The nighttime boundary layer of Mars as predicted by large-eddy simulations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9049, https://doi.org/10.5194/egusphere-egu23-9049, 2023.

The focus of this presentation is the three-dimensional visualization of Mars dust storms from spacecraft images. The dust storm height is determined by their shadows. Image parameters such as the solar incidence angle, solar azimuth angle, latitude, and longitude are taken into account. Interactive three-dimensional maps of dust storms are created. This presentation includes satellite images from MARCI/MRO (Mars Color Imager/Mars Reconnaissance Orbiter) in the years 2020-2021. This adds to a better understanding of Mars dust storms. This works uses the MeteoMARS tool [1], the NASA PDS Imaging Node [2], the NASA Integrated Software for Imagers and Spectrometers, and the QGIS software [3].

[1] http://meteomars.pamplonetario.org/

[2] https://pds-imaging.jpl.nasa.gov/

[3] https://www.qgis.org/en/site/

How to cite: Alzeyoudi, M. and Gebhardt, C.: The Three-Dimensional Visualization of Mars Dust Storms Based on Deriving Digital Elevation Maps from Satellite Imagery, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3247, https://doi.org/10.5194/egusphere-egu23-3247, 2023.

This presentation adds to Mars dust storm research based on numerical models and spacecraft images. The focus is the conversion of MarsWRF model data into synthetic satellite images of Mars dust storms. MarsWRF is a Mars version of the terrestrial numerical weather and climate model WRF (Weather Research and Forecasting Model) and part of the PlanetWRF models for planetary atmospheres research. Dust storms are obtained by running the MarsWRF model with the interactive-dust-lifting-technique [1]. Synthetic satellite imagery is generated from MarsWRF model data by using the radiative transfer model DISORT, which provides the top-of-the-atmosphere reflectance data. The results are synthetic satellite images, mostly for visible light wavelength. We compare synthetic satellite images of dust storm events at different times of the Martian Year.

[1] Gebhardt, C., Abuelgasim, A., Fonseca, R. M., Martín-Torres, J., & Zorzano, M.-P. (2020). Fully interactive and refined resolution simulations of the Martian dust cycle by the MarsWRF model. Journal of Geophysical Research: Planets, 125, e2019JE006253. https://doi.org/10.1029/2019JE006253

How to cite: Alkaabi, F. and Gebhardt, C.: Synthetic satellite images of Mars dust storms based on MarsWRF dust cycle simulations and the radiative transfer model DISORT, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3435, https://doi.org/10.5194/egusphere-egu23-3435, 2023.

In order to facilitate human exploration on Mars, a need exists to study weather patterns and atmospheric conditions on Mars. Mars has colder weather than Earth, is known for its dust storms, and has a very thin atmosphere, yet its atmosphere and climate are more like Earth's than any other planet in our solar system. Despite these challenges, NASA scientists believe that Mars is the most promising planet for exploration and habitation. We are developing a new measurement concept that uses differential absorption Lidar system in the 2-μm CO₂ absorption band to measure atmospheric CO₂ and pressure on Mars. By selecting two or more closely spaced wavelengths, one can eliminate the effects of other gases and surface reflections, allowing us to accurately measure CO₂ absorption and determine CO₂ levels and air pressure on Mars. Our simulations show that this system will be able to measure air pressure with 1 Pa precision up to 5 km away, even in the presence of moderate dust, and measure CO₂ and pressure profiles from the surface up to 13 km with a horizontal resolution of 100 km and a vertical resolution of 100 m (400 m during the day). These measurements will improve weather and climate modeling and prediction on Mars.

How to cite: Campbell, J., Liu, Z., Lin, B., Yu, J., and Jiang, S.: Martian Atmospheric Pressure Measurement from Space, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16660, https://doi.org/10.5194/egusphere-egu23-16660, 2023.

The Atmospheric Chemistry Suite (ACS) on the ExoMars Trace Gas Orbiter (TGO) took its first science observation in April 2018, right before the onset of the Mars Year (MY) 34 global dust storm. One of the main objectives of the TGO mission is to search for as-yet undetected trace gases that can tell us about contemporary volcanism on Mars, or its present and past habitability. In the data collected those first months, heavily impacted by dust activity, the first novel trace gas was discovered: hydrogen chloride. MY 37 has just begun and we have recently finished observing our third full dusty season on Mars with TGO and ACS (around perihelion, spring and summer in the southern hemisphere). HCl in the atmosphere of Mars is a seasonal phenomenon, having appeared coincidentally with the start of dust activity in each MY. HCl was thought to be an indication of contemporary volcanism, but its widespread distribution across both hemispheres and recurring seasonality are suggestive of a photochemical source. Here, we present the climatology of HCl after three Martian perihelion periods, as well as a comparison with other parameters measured with ACS, such as water, temperature, and aerosols. From coincident measurements made with the Mars Climate Sounder (MCS) on Mars Reconnaissance Orbiter (MRO), we can also compare the climatology of HCl with those of dust and water ice. HCl is strongly correlated to water vapour, which is itself correlated to atmospheric temperatures. While HCl only appears in the presence of suspended dust aerosols, the measured abundances of these two quantities are poorly correlated. The disappearance of HCl towards the autumnal equinox may be related to changes in temperature. The cooling atmosphere removes water vapour from the gas phase, necessary for formation of HCl, and promotes ice formation, which HCl may adhere to. We will show the evolution of HCl abundance over three Martian years in both hemispheres, and show how they fit into the seasonality of Martian dust, the water cycle, and ice formation, and discuss the possible mechanisms of its formation and destruction.

How to cite: Olsen, K. S., Trokhimovskiy, A., Fedorova, A. A., Kleinbohl, A., Lefèvre, F., Montmessin, F., Korablev, O. I., Alday, J., Baggio, L., Belyaev, D. A., Patrakeev, A. S., Shakun, A., and Patel, M.: The chlorine cycle on Mars: What do we know after three Mars years of observation with ACS on TGO?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16154, https://doi.org/10.5194/egusphere-egu23-16154, 2023.

We develop a 1-D atmospheric photochemistry model for Mars to interpret hydrogen chloride (HCl) profile measurements collected by the ACS MIR spectrometer aboard the ExoMars Trace Gas Orbiter (TGO) in Mars Year (MY) 34. We include a gas-phase chlorine chemistry scheme and study 1) surface chemistry, 2) hydrolysis, 3) photolysis, and 4) hydration and photolysis of dust grains as possible sources of gas-phase chlorine chemistry. Heterogeneous uptake of chlorine species onto water ice and minerals in Martian dust are loss processes common to all mechanisms. We drive the 1-D model using TGO profile measurements of aerosols and water vapour. We find that mechanism four can reproduce observed HCl profile tendencies during MY34. It reproduces the HCl cut-off at high southern latitudes (<60° S) at ≈35 km, and forms layers of HCl between 20-35km at the tropics. Mechanisms one, two, and three result in significant model biases.

Seasonal variations of Martian HCl are reproduced by mechanism four, yielding low HCl abundances (< 1 ppb) prior to the dust season that rise to 2--6 ppb in southern latitudes during the dust season. We find that the additional Cl atoms released via mechanism four shortens the atmospheric lifetime of methane by a magnitude of 10². This suggests the production of Cl via the UV (or other electromagnetic radiation) induced breakdown of hydrated perchlorate in airborne Martian dust, consistent with observed profiles of HCl, helps reconcile observed variations of methane with photochemical models.

How to cite: Taysum, B. M., Palmer, P. I., Luginin, M., Ignatiev, N., Trokhimovskiy, A., Shakun, A., Grigoriev, A., Montmessin, F., Korablev, O., and Olsen, K.: Martian atmospheric chemistry of HCl: implications for the lifetime of atmospheric methane, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17592, https://doi.org/10.5194/egusphere-egu23-17592, 2023.

Solar wind protons can interact directly with the hydrogen corona of Mars through charge exchange, resulting in energetic neutral atoms (ENAs) able to penetrate deep into the upper atmosphere of Mars. ENAs can undergo multiple charge changing interactions, leading to an observable beam of penetrating protons in the upper atmosphere. We seek to characterize the behavior of these protons in the presence of magnetic fields using data collected by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. We find that backscattered penetrating proton flux is enhanced in regions where the magnetic field strength is greater than 200 nT. We also find a strong correlation at CO₂ column densities less than 5.5 × 10¹⁴ cm⁻² between magnetic field strength and the observed backscattered and downwardflux. We do not see significant changes in penetrating proton flux with magnetic field strengths on the order of 10 nT.

How to cite: Henderson, S., Halekas, J., Espley, J., and Elrod, M.: Influence of Magnetic Fields on Precipitating Solar Wind Hydrogen at Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-985, https://doi.org/10.5194/egusphere-egu23-985, 2023.