The rich meteorology of Jezero crater over the first 250 sols of Perseverance on Mars

Abstract 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.