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The Mars2020 Perseverance Rover landed successfully on the Martian surface on the Jezero Crater floor (18.44°N, 77.45°E) at Martian solar longitude, $L_s$, $\sim$5 in February 2021. Since then it has produced highly valuable environmental measurements with a versatile scientific payload including the MEDA (Mars Environmental Dynamics Analyzer) suite of environmental sensors. One of the MEDA systems is the PS pressure sensor system which weighs 40 grams and has an estimated absolute accuracy of better than 3.5 Pa and a resolution of 0.13 Pa. We present initial results from the first 414 sols of Martian atmospheric surface pressure observations by the PS whose performance was found to meet its specifications. Observed sol-averaged atmospheric pressures follow an anticipated pattern of pressure variation in the course of the advancing season and are consistent with data from other landing missions. The observed diurnal pressure amplitude varies by $\sim$2-5 \% of the sol-averaged pressure, with absolute amplitude 10-35 Pa in an approximately direct relationship with airborne dust. During a regional dust storm, which began at $L_s~135^\circ$ the diurnal pressure amplitude roughly doubles. The diurnal pressure variations were found to be remarkably sensitive to the seasonal evolution of the atmosphere. In particular analysis of the diurnal pressure signature revealed diagnostic information likely related to the regional scale structure of the atmosphere. Comparison of Perseverance pressure observations to data from other landers reveals the global scale seasonal behaviour of Mars’ atmosphere.

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.

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.

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.

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.

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).

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 paperFigure. 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.

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.

Clinical supervision may support forensic mental health nurses with personal and professional growth in a work environment characterized by therapeutic, ethical, and practical challenges.The aim of this study was to describe the experiences of forensic mental health nurses participating in a clinical supervision program.Seven forensic mental health nurses and two allied health professionals, working in a high-security forensic mental health hospital, were interviewed regarding their experiences of participating in a clinical supervision program.Participants expressed a need for clinical supervision and were motivated to participate in the program. Benefits of clinical supervision experienced by participants included improved communication with their colleagues, being supported in their career development, and developing habits and techniques to reflect on practice issues. Participants described being able to connect with their supervisor, enabled by both trust and confidence in the supervisor's expertise.Staff showed engagement in the clinical supervision process and expressed experiencing positive outcomes related to personal and professional growth and development.To support nurses with the forensic mental health context-specific challenges they face, organizations should enable and promote access to clinical supervision. Considerations for forensic mental health organizations to increase uptake and effectiveness of clinical supervision include use of externally based clinical supervisors with adequate skills and experience with providing clinical supervision to clinical staff who work in a secure environment.

The Mars Environmental Dynamics Analyzer (MEDA) instrument, on board the NASA’s Mars 2020 Perseverance rover, includes a number of sensors to characterize the Martian atmosphere. One of this sensors is the Radiation and Dust Sensor (RDS) that measures the solar irradiance at different wavelengths and geometries. We analyzed the RDS observations made during twilight for the period between sol 71 and 492 of the mission (Ls 39◦-262◦) to characterize the clouds over the Perseverance rover site. Using the ratio between the irradiance at zenith at 450 and 750 nm, we inferred that the main constituent of the detected high-altitude aerosol layers was ice from Ls= 39◦ to 150◦ (cloudy period), an dust from Ls 150◦-262◦. A total of 161 twilights were analyzed in the cloudy period using a radiative transfer code and we found: i) signatures of clouds/hazes in the signals in the 58 % of the twilights; ii) most of the clouds had altitudes between 40-50 km, suggesting water ice composition, and had particle sizes between 0.6 and 2 μm; iii) the cloud activity at sunrise is slightly higher that at sunset, likely due to the differences in temperature; iv) the time period with more cloud detections and with the greatest cloud opacities is during Ls 120◦-150◦; and v) a notable decrease in the cloud activity around the aphelion, along with lower cloud altitudes and opacities. This decrease in cloud activity indicates lower concentrations of water vapor or cloud condensation nuclei (dust) around this period in the Martian mesosphere.

Since February 18, 2021, Perseverance has been exploring Jezero Crater (18ºN, 77ºE). The meteorology of this location is being investigated with the Mars Environmental Dynamics Analyzer (MEDA) [1], which among many other sensors has 5 Air Temperature Sensors (ATS) to measure near surface temperatures. These sensors are located at two altitudes: two are at 0.85 m, in the front of the rover, and three are at 1.45 m around the Remote Sensing Mast (RSM), distributed azimuthally so that at least one sensor is located upwind. Local air temperatures are measured with a frequency that can be as high as 2 Hz. In addition, the temperature of the surface and at an approximate altitude of about 40 m are measured with the Thermal Infrared Sensor (TIRS), which operates with a sampling frequency of 1 Hz. MEDA records atmospheric variables typically over 50% of a full sol. Here we present consolidated analysis of data up to sol 400, which covers a period from the start of northern Spring (Ls=5º) to early Autumn (beyond Ls=180º). This analysis takes into account different instrumental effects affecting ATS and TIRS which have been characterized over the course of the mission. Firstly, we will present the daily temperature cycle at Jezero, including mean values and its fluctuations plus their daily and seasonal evolution. Hence, we report phenomena at various altitudes, in different time scales, ranging from thermal tides to continuous rapid fluctuations, as well as the effects caused by the different environments as Perseverance explores Jezero. The convective and calmed regimes, at daytime and nighttime respectively, and the transitions between them are well differentiated in the MEDA data and can be well characterized. We will also discuss vertical thermal gradients (surface to 40 m altitude) along the mission and the evolution of nighttime inversions. Secondly, we quantify the influence of different forcings on temperatures: The thermal changes associated with clouds, dust load, variations of the solar flux and changes in the surface properties on the ground and near-surface temperatures. Specific effects associated with a regional dust storm over Jezero will be presented. Lastly, we will comment on the comparison of temperatures at Jezero with in situ data from other locations [2-3] and models [4-5]. [1] Rodriguez-Manfredi, J. A., et al. (2021). The Mars Environmental Dynamics Analyzer, MEDA. A suite of environmental sensors for the Mars 2020 mission. Space science reviews, 217(3), 1-86. [2] Davy, R., et al. (2010). Initial analysis of air temperature and related data from the Phoenix MET station and their use in estimating turbulent heat fluxes. Journal of Geophysical Research: Planets, 115(E3). [3] Mason, E. L., & Smith, M. D. (2021). Temperature fluctuations and boundary layer turbulence as seen by Mars Exploration Rovers Miniature Thermal Emission Spectrometer. Icarus, 360, 114350. [4] Newman et al. (2020). Multi-model Meteorological and Aeolian Predictions for Mars2020 and the Jezero Crater Region, Space Sci. Rev. 215, 148. [5] Pla-García et al., (2020). Meteorological Predictions for Mars 2020 Perseverance Rover Landing Site at Jezero, Space Sci. Rev., 215, 148.

The aim of this investigation is to carry out a study of the variability of nocturnal atmospheric turbulence at Jezero crater supported by modeling effort and monitored by MEDA. The rapid turbulent kinetic energy (hereafter TKE), wind and pressure fluctuations observed during nighttime both with modeling and MEDA is a clear indicator of nocturnal turbulence. The origin of this nocturnal turbulence is explored with MRAMS and, as opposed to Gale crater, low evidence of significant gravity waves activity during the whole period studied was found. On the contrary, the nighttime turbulence at Jezero crater could be shear driven and may be explained due to an enhanced mechanical turbulence produced by increasingly strong shear (onset of a strong low-level jet) at the nocturnal inversion interface. As the nocturnal inversion develops, the winds above become decoupled from the surface and the decrease in friction produces a net acceleration [refs 4, 5, 6, 7]. Once the critical Richardson Number is reached (Ri ∼< 0.25, Figure 3), shear instabilities can mix warmer air aloft down to the surface [refs 8, 9, 10]. 1. Introduction The Mars 2020 Perseverance rover landed in Mars in February 2021 at 18.44°N 77.45°E within and near the northwest rim of Jezero crater. The MEDA weather station is aboard Perseverance rover [ref 1]. 2. MRAMS mesoscale simulations MRAMS was applied to Mars 2020 landing site region using nested grids with a spacing of 330 meters on the innermost grid that is centered over the landing site [ref 2]. 3. Nighttime turbulence modeled with MRAMS The effect of subgrid-scale eddies is captured within MRAMS via a prognostic TKE (Figure 1) equation [ref 3]. MRAMS shows a peak in TKE during the afternoon, which is consistent with the modeled high-frequency variations in air temperatures [Figure 3 of ref 2]. The sudden increase in air temperature during the evenings [Figure 3 of ref 2] at the onset of radiative cooling is produced by mechanically driven turbulence since the atmosphere is stable and non-convective in the evening. The model does often show small increases of TKE during the night (Figure 1), especially during Ls=180º (corresponding to Mars 2020 sol 362) and some during Ls 105 and Ls 160 (corresponding to Mars 2020 sols 216 and 326), that could be associated with the turbulent aspects of the nighttime dynamical flows when compared with nearby locations with more flat topography. During the late evening and night, MRAMS is resolving thermal variations [2, Figure 3] and does often show small increases of TKE at that time (Figure 1). The rapid air temperature fluctuations modeled at night in all seasons is indicative of nocturnal turbulence. There is low evidence of significant wave activity during the whole period studied and only some gravity waves were found. The nighttime turbulence could be attributed to shear driven turbulence and may be explained due to an enhanced mechanical turbulence driven by increasingly strong shear, with the onset of the nocturnal low-level jet, at the nocturnal inversion interface (an example on Figure 2). Based on GCM model efforts, looks like the low-level jet is a large scale circulation feature. The westward wind at 2 km altitude shown on Figure 2 is also show up nicely in the MCD. The jet could be forced by the diurnal cycle. The dustier atmosphere, when arrival of northern autumn equinox, also contributes to decrease the nighttime Richardson number by two means: strengthening of the nighttime low-level jet deeping the near-surface wind shear and weakening near-surface atmospheric stability by increasing the nighttime surface temperature and decreasing of atmospheric temperature. A third possible strengthening of the nighttime turbulence at Jezero could be the convergence, after 01:00 LTST, of downslope winds blowing from NW rim fighting against SE winds blowing both from east crater rims and from Jezero mons (located SE outside the crater), producing a big whirlpool inside the crater (Figure 4) that could be the responsible of the high variability of wind directions observed by MEDA. 4. Nightime turbulence observed with MEDA The rapid fluctuations of pressure (moreover during high dust periods), TKE (derived only with horizontal wind speeds, that will be updated with vertical winds in the future) and wind speeds observed during nighttime with MEDA (Figures 5 and 6) is a clear indication of nocturnal turbulence. 5. Figures Figure 1: TKE diurnal cycle predicted with MRAMS for Jezero crater at Ls0, 60, 90, 105, 160, 180 and 270. Figure 2: MRAMS vertical cross-section (Jezero’s west rim to east rim) at 21:35 LTST of Ls=180º -corresponding to Mars 2020 sol #362- of total wind (zonal + meridional) in colored shadowed, zonal + vertical (exaggerated x5) wind in white arrows and TKE in black contours. The west crater rim is the hill on the left. Perseverance rover is located at x ≈ 17 km. Figure 3: MRAMS vertical profiles of wind magnitude, wind shear, Richardson number (Ri) and TKE for Ls180 at Mars 2020 location corresponding to Mars 2020 sol #362 (Ls=180º). Once the critical Richardson Number is reached (Ri ∼< 0.25, red line). Figure 4: Near-surface winds (vectors) and potential temperature (shaded) as predicted on numerical grid 5. Vectors are plotted at every other grid point. Topography contours are shown in black. Wind vector scale is shown in the bottom right area of the panels. hh:mm LTST on the top right. A big whirlpool inside the crater could be responsible for the large variability of wind directions observed by MEDA after 01:00 LTST. Figure 5: MEDA TKE (derived only with horizontal wind speeds, that will be updated with vertical winds in the future), wind direction and horizontal wind speed instantaneous measurements for the period 00:14 to 00:23 LTST at sol #73. Figure 6: Diurnal cycle of MEDA TKE averaged over 5 min for sols #73-87. 6. References [1] Rodriguez-Manfredi et al. 2020; [2] Pla-Garcia et al. 2021; [3] Mellor and Yamada 1974; [4] Davis 2000; [5] Blackadar 1957; [6] Thorpe and Guymer 1977; [7] Mahrt 1981; [8] Miles 1961; [9] Banfield et al. 2020; [10] Chatain et al. 2021

The Mars 2020 Perseverance rover is developing its mission in Jezero crater [1], a north tropical location that is rich in vortices and dust devils [2]. The MEDA instrument [3] collects atmospheric data at a typical frequency of 1 Hz with several sensors including pressure and winds. It also registers data about atmospheric dust with its set of photodiodes [4]. Together, these data are providing a large set of detections of vortices and dust devils [2, 5] that can be used to investigate the physical properties of the vortices and their effects on the environment though the combination of additional data obtained by MEDA. Here we present a physical characterization of dust devils detected with the pressure data and confirmed as dust devils from the set of photodiodes on MEDA. We show that the combination of pressure, winds and a simple model of drifting vortices [6] can fit the observations of many of these events determining their true central pressure drop, diameter and maximum circulation winds. The quality of the comparisons depend on the varying quality of the wind measurements and is better in short encounters with small vortices than in long encounters with large dust devils. We examine how the vortices characteristics, i.e. their true diameter, minimum distance of the encounter, central pressure drop and maximum wind intensity compare with the detection of dust and its basic inferred abundance and explore the consequences for the efficiency of vortices of different sizes and intensities to raise dust from the Martian surface. We also compare these vortex parameters with environment thermal properties, such as the thermal gradient from the surface and the air, and the thermal perturbations caused by the vortex in a selection of the best observed cases. A comparison with main properties of vortices observed in the different surveys of dust devil activity carried on by the cameras onboard Perseverance will be also presented. References:[1] Farley, K.A. et al. Mars2020 Mission Overview, Space Sci. Rev., 216, 142 (2020). Doi: 10.1007/s11214-020-00762-y[2] Newman, C.E. et al. The dynamic atmospheric and aeolian environment of Jezero crater, Mars, Science Advances (in press).[3] Rodriguez-Manfredi, J.A. et al. The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission, Space Science Reviews, 217, 48 (2021), doi:10.1007/s11214-021-00816-9.[4] Apestigue, V. et al. Radiation and Dust Sensor for Mars Environmental Dynamic Analyzer Onboard M2020 Rover. Sensors, 22, 2907 (2022). doi:10.3390/s22082907[5] Jackson, B. Vortices and Dust Devils as Observed by the Mars Environmental Dynamics Analyzer Instruments on Board the Mars 2020 Perseverance Rover, The Planetary Science Journal, 3, 20 (2022). Doi: 103847/PSJ/ac4586[6] Lorenz, R., Heuristic estimation of dust devil vortex parameters and trajectories from single-station meteorological observations: Application to InSight at Mars. Icarus, 271, 326-337 (2016). doi: 10.1016/j.icarus.2016.02.001

The objective of this study is to identify the dominant atmospheric wave modes driving and maintaining superrotation on Titan, by using a combination of space-time cross spectral wave analysis and spherical harmonic wave analysis techniques. A defining feature of Titan’s atmospheric circulation is the presence of strong, planet-wide superrotation in the stratosphere. To achieve and sustain equatorial superrotation, angular momentum must be transported up the angular momentum gradient, which can only be accomplished by wave transport [2]. Newman et al. (2011) showed that equatorial superrotation can be maintained via episodic “transfer events,” in which barotropic instability leads to the generation of planetary-scale waves that carry angular momentum and speed-up the equatorial flow [3]. Yet the origin and nature of these waves in the real atmosphere, and the exact mechanisms driving superrotation and upper atmospheric wave forcing, remain unknown. We simulated the Titan atmosphere using the Titan Weather Research and Forecasting (TitanWRF) model and evaluated the temperature and momentum perturbations at different times during one full Titan year of simulation output. Fourier transforms of the temperature and wind fields showed that a strong correlation can be established between wave amplitude and angular momentum transfer events. Power spectral density for eddy heat and eddy momentum as a function of altitude, latitude, and phase speed or zonal wavenumber further emphasized the correlation. In our simulation, the largest angular momentum transfer event occurred around Ls~261°. Two additional transfer events were found at Ls~116° and Ls~192°, along with a number of smaller events occurring throughout the year. References: [1] Charnay et al. (2015) Nature Geosci, 8, 362–366. [2] Gierasch (1975) J. Atmos. Sci., 32, 1038–44. [3] Newman et al. (2011) Icarus, 213, 636–654.

Perseverance's Mars Environmental Dynamics Analyzer (MEDA) is collecting data at Jezero Crater, characterizing the physical processes in the lowest layer of the atmosphere as no previous instrument did before. Here we show that temperature measurements at four heights capture the response of the atmospheric surface layer to multiple phenomena. We observe the transition from a stable nighttime thermal inversion to a diurnal, highly turbulent convective regime, with large vertical thermal gradients, and where local surface properties (such as Thermal Inertia) play an essential role. Recording multiple daily optical depths yielded higher aerosol concentrations in the morning than in the afternoon. Measured wind patterns are mainly driven by local topography, with a small contribution from regional winds. Daily and seasonal variability of relative humidity shows a complex hydrologic cycle. These observations raise new puzzles in which changes in surface albedo and thermal inertia may play an influential role. On a larger scale, surface pressure shows typical signatures of gravity waves and baroclinic eddies in a part of the seasonal cycle characterized before as low wave activity. These observations, combined and simultaneous, show the rich Jezero’s meteorology, and unveil the diversity of processes driving change on today’s Martian surface.

The Mars Environmental Dynamics Analyzer (MEDA) is a meteorological station onboard Mars 2020 that characterizes the near surface atmosphere. Among other sensors MEDA has 5 Air Temperature Sensors (ATS) at two altitudes: 0.85m, in the front of the rover, and 1.45m around the Remote Sensing Mast, which are azimuthally distributed so that at least one sensor is located upwind. This configuration ensures that, for most environmental conditions, the thermal contamination caused by the rover can be set apart. Local air temperatures are read with a frequency of 1 or 2 Hz, and ATS data can characterize timescales from atmospheric turbulence to the daily temperature cycle and its seasonal evolution. Here we show the daily temperature cycle at Jezero and an analysis of its seasonal evolution over the first half Martian year of the mission from Spring (Ls=6) to Autumn Equinox (Ls=180). Simultaneous ATS and winds from MEDA’s wind sensors show that, for most rover orientations, solar irradiation and winds clean environmental measurements are obtained at the 1.45m level. However, clean measurements at the 0.85m level are not always fully achieved, and a small residual thermal contamination is found at this level in many measurement sessions. The daily temperature cycle reflects the daily cycle of convection and turbulence. Strong and fast thermal oscillations start a few hours after sunrise, peak near noon, and collapse before sunset. The seasonal evolution shows a progressive increase of temperatures as summer advances, but less steep than what is retrieved at other Martian locations by previous missions. At the 0.85m level, changes in atmospheric temperatures with time-scales of a few sols correlate well with variations in local terrain properties. At the 1.45m level, similar temperature changes with timescales of a few sols are also found. We investigate whether these changes at 1.45m can be associated with changing atmospheric opacity due to dust and clouds, which are measured by other MEDA sensors and additional instruments in Perseverance. From the two altitudes sampled with ATS, and additional data from the MEDA Thermal InfraRed Sensors (TIRS), which measure ground temperature and air temperature at 40m, we can obtain the near-surface vertical temperature profile for specific sols in which thermal contamination is moderate in all sensors. This allows us to study the evolution of the diurnal convective cycle and the vertical temperature gradient. In addition, the Supercam microphone can also deduce the average air temperature from the ground up to 2.1m high thanks to sound speed measurements during Supercam’s laser zapping rocks. Therefore, it gives an additional hint into the thermal gradient. Furthermore, the amplitude of the thermal oscillations characterizes the thermal turbulence and we present the spectra of turbulence for convective and non convective hours on different moments of the mission. Finally, we will show how the measured thermal data compares with model predictions of the daily cycle of temperatures, expected magnitude of thermal oscillations, and the seasonal evolution.

The Mars 2020 Perseverance rover landed in Mars in February 2021 in Jezero crater at 18.4ºN. One of its instruments is MEDA, the Mars Environmental Dynamics Analyzer, which measures among other properties air pressure, air temperature at different levels, surface temperature from its infrared emission, and the presence of dust. The latter is provided by a set of photodiodes pointing in different directions that constitute the Remote Dust Sensor or RDS. MEDA data are acquired with a frequency of 1 or 2 Hz in data sessions that cover about 50% of a full sol allowing a full characterization of daily and seasonal cycles.Predictions before landing indicated that Jezero should be a location favoring the formation of intense vortices and dust devils in Spring to Summer. These expectations were fulfilled with frequent observations of vortices and dust devils observed with MEDA and the rover cameras. A systematic analysis of MEDA’s pressure sensor shows the close passage of convective vortices. These are detected as events that range from short and sharp pressure drops to long and deep pressure drops. Wind measurements during the vortex passage, combined with their duration, give information about the size and distance of the vortex. Many of the most intense events in terms of the pressure drop and peak winds detected have simultaneous drops of light measured with the RDS and are dust devils equivalent to those observed at much higher distances with Perseverance cameras. The combination of pressure, wind and RDS measurements largely constrain the geometry effects associated to these close passing dust devils. Some of them also have additional clear counterparts in other MEDA sensors including temperatures, which allows for an in-depth investigation of the physical properties of selected dust devils. Some events might also be captured by the SuperCam microphone, that records pressure fluctuations in the audible domain. The acoustic signal can provide insights into the short term behavior of vortices, and can contribute to the determination of the vortex physical properties. Statistics of vortices allow us to determine the probability of finding these events with the SuperCam microphone.We present results for over one Earth year (Ls=6; Feb. 2021, Northern Hemisphere Spring – Ls=180; Feb. 2022; Northern Autumn Equinox). We show the daily cycle of vortex and dust devil activity and how this has evolved from early Spring until the start of the dust storms season. We present results of the distribution of sizes of vortices and dust devils and a selection of some remarkable events. These include direct hits of dust devils passing right through Perseverance, tangential passes in which one wall of the vortex passes over Perseverance, and more distant passages of very dusty events whose diameter in some cases largely exceed 100 m. A comparison of the vortex convective activity observed at Jezero with results from a Large-Eddy-Simulations (LES) using the MarsWRF model helps us to gain insight into how the detected vortices and their properties can constrain other general properties of the atmospheric dynamics at Jezero crater.

Observations of the South Polar Residual Cap suggest a possible erosion of the cap, leading to an increase of the global mass of the atmosphere. We test this assumption by making the first comparison between Viking 1 and InSight surface pressure data, which were recorded 40 years apart. Such a comparison also allows us to determine changes in the dynamics of the seasonal ice caps between these two periods. To do so, we first had to recalibrate the InSight pressure data because of their unexpected sensitivity to the sensor temperature. Then, we had to design a procedure to compare distant pressure measurements. We propose two surface pressure interpolation methods at the local and global scale to do the comparison. The comparison of Viking and InSight seasonal surface pressure variations does not show changes larger than +-8 Pa in the CO2 cycle. Such conclusions are supported by an analysis of Mars Science Laboratory (MSL) pressure data. Further comparisons with images of the south seasonal cap taken by the Viking 2 orbiter and MARCI camera do not display significant changes in the dynamics of this cap over a 40 year period. Only a possible larger extension of the North Cap after the global storm of MY 34 is observed, but the physical mechanisms behind this anomaly are not well determined. Finally, the first comparison of MSL and InSight pressure data suggests a pressure deficit at Gale crater during southern summer, possibly resulting from a large presence of dust suspended within the crater.

On top of listening to laser shots, rover sounds and the Ingenuity rotorcraft, SuperCam’s Mars microphone has recorded over 7 hours of ambient background noise on Mars. These background recordings contain signal due to the Martian wind. Through a comparison to the meteorological data recorded by the MEDA (Mars Environmental Dynamics Analyzer), we can determine the relationships between the microphone data, the wind and the atmospheric stability. Based on these relationships, we have determined a way to estimate the wind speed using the microphone through Gaussian process regression, a machine learning technique. Owing to the sampling rate of 25 000 samples per second, the microphone data can be used to examine Mars’ atmospheric dynamics at high frequencies, as yet unexplored on Mars. We will demonstrate how the wind speed estimates from the microphone provide an assessment of turbulence at fine scales, shedding light on the dissipative regime on Mars. One particularly interesting signal recorded by the microphone was a dust devil, which had fast varying winds within the walls of its vortex and signal from dust particles hitting the rover. Combining the microphone data with information from the MEDA sensors and navigation camera (Navcam) images enabled a full parameterization of this event.

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