Physical characterization of dust devils at Jezero crater from Mars2020/MEDA data

<p>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.</p><p>&#160;</p><p><strong>References:</strong></p><p>[1] Farley, K.A. et al. Mars2020 Mission Overview, Space Sci. Rev., 216, 142 (2020). Doi: 10.1007/s11214-020-00762-y</p><p>[2] Newman, C.E. et al. The dynamic atmospheric and aeolian environment of Jezero crater, Mars, Science Advances (in press).</p><p>[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.</p><p>[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</p><p>[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</p><p>[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</p>