Presentation #206.06 in the session “Mars: From the Surface to the Atmosphere”.
Since the Perseverance rover’s arrival in February 2021, atmospheric and aeolian observations by a wide range of rover instruments have revealed a highly dynamic environment in Jezero crater. The Mars Environmental Dynamics Analyzer (MEDA) carries a large suite of meteorological sensors, including pressure, surface temperature and atmospheric temperature at three heights, relative humidity, and wind speed and direction, as well as sensors dedicated to measuring aerosol abundance and properties, and (for the first time on Mars) upward and downward visible and infrared radiative fluxes. The SuperCam instrument has been used to measure atmospheric gas and aerosol abundances and aerosol properties, and also carries the first microphone operating on the martian surface, which has been used to measure very high frequency wind variations. Further, Mastcam-Z and the rover’s engineering cameras have been used to retrieve aerosol abundances and properties, to observe clouds, dust devils, and dust lifting, and to observe aeolian features at the surface.
Perseverance’s wind measurements reveal diurnal and seasonal patterns of winds driven by the global and regional Isidis basin circulation, as well as significant sol-to-sol variability and strong wind gusts that may be associated with vigorous daytime convection cells being advected over the crater. These may also be linked to several strong dust lifting events imaged since landing. Measurements of pressure, temperature, wind, and radiative fluxes by MEDA sensors have been used to identify and even track the passage of vortices and dust devils, while rover cameras have caught numerous dust devils in images. Surface features such as regolith wind tails and ventifacts also indicate major aeolian activity inside the crater, although their orientations and morphology suggest the ventifacts may have formed under past climate conditions.
Collectively, these observations show Jezero crater to be one of the most dynamic environments we have visited on Mars. In this presentation we will examine the diurnal, sol-to-sol, and seasonal variations of winds, wind gusts, and vortices; explore how these changes may be controlled by solar insolation, local topography, atmospheric waves, and regional and global-scale circulations; and relate these observations to observed dust lifting and aeolian features.