An Updated Catalog of Vortices and Dust Devils on Jezero Crater, Mars from MEDA data

The MEDA instrument on Mars 2020 has been operating on the surface of Mars for more than 1500 sols obtaining measurements of pressure, temperature and other environmental properties with a fast cadence. Vortices and dust devils appear often in the MEDA measurements obtained by the pressure sensor and the Radiation and Dust Sensor (RDS) suite, and the vortex signature is some times present in other MEDA sensors, particularly on the Thermal and Infrared Sensor (TIRS). Current data covers a period of nearly 2 Martian years that allows a deep investigation of the properties of dust devils on the Jezero area. We identify the close approaches of vortices to the Perseverance rover from pressure drops measured with MEDA and identified by a search algorithm that uses a variety of time windows to find and characterize both short and long pressure drops [1, 2]. Some of these vortices are identified as dust devils from simultaneous or nearly simultaneous drops of light measured by the RDS Top sensor [3].

Seasonal variability repeats similarly over 2 Martian Years but interannual variability is also observed. Dust devil activity peaks over summer at Ls=150º-160º and strongly declines in the autumn to early winter season, especially during Martian Year 37 around sol 1200 of the mission. The inter-annual variability is linked to varying properties of the terrain over the traverse followed by Perseverance as it explores different terrains from the crater floor to the crater rim and the delta over an accumulated distance of 35 km. Some particularly intense events with pressure drops as deep as 7.7 Pa raise significant amounts of dust. The trajectory of these very strong dust devils can be studied by the RDS lateral sensors, thus, constraining the geometry of the encounter and the physical properties of the dust devil. A combined dataset of nearly 4,000 vortices and nearly 700 dust devils will be presented. For a small subset of events, we investigate ranges of models of drifting vortices that can fit the diameter and closest approach to the vortex encounter from the combination of pressure and RDS data.

References: [1] Newman et al. The dynamic atmospheric and aeolian environment of Jezero crater, Mars.Science Advances, 8, eabn3783 (2022) 25 May 2022, doi: 10.1126/sciadv.abn378 (2022). [2] Hueso et al. Convective vortices and dust devils detected and characterized by Mars 2020, Journal of Geophysical Research Planets, 128, e2022JE007516,  https://doi.org/10.1029/2022JE007516 (2023). [3] Toledo et al. Dust devil frequency of occurrence and radiative effects at Jezero crater, Mars, as measured by MEDA Radiation and Dust Sensor (RDS)  Journal of Geophysical Research: Planets, 128, e2022JE007494, doi: https://doi.org/10.1029/2022JE007494 (2023).