Dust Devil frequency of occurrence at Jezero crater and radiative effects as derived by MEDA-RDS

<p>The dust cycle dominates Mars's meteorology. Studying the dust injection into the atmosphere is crucial to understanding and modeling the planet's climate. The Mars Environmental Dynamics Analyzer (MEDA) [1], on board the Perseverance rover, is a meteorological station than has been operating on Mars's surface for more than 400 sols [2]. One of the main goals of MEDA is to study the Mars dust cycle, and for this purpose, it includes the Radiation and Dust Sensor (RDS) [3], among other instruments. This instrument contains two different sensing technologies for dust characterization: a CCD camera looking at the sky and a radiometer based on silicon detectors arranged in different orientations. As a result of the RDS field of view, the number of sensors, and low power consumption and data volume, this sensor is capable of detecting and characterizing dust lifting events such as dust devils for extended periods (of hours) and at a high sampling frequency (1 Hz). Moreover, for the cases with multiple RDS detections and wind sensor observations, the trajectory and dust devil geometry can be derived.</p> <p>In this work, we have estimated for the first 365 sols: i) the number of dust devils formed at Jezero (expressed in number per area and unit of time); ii) the dust devil impact on the irradiance levels on the surface at different wavelength ranges (e.g. UV or 190-1200 nm ranges); iii) the dust devil spatial distribution along the rover traverse; and iv) the dust devil geometry (diameter and altitude) and trajectory for some of the events. For these analyses, we made used of radiative transfer and Monte-Carlo trajectory simulations. We will also discuss the implications of these results on the Mars dust cycle.    </p> <p>[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.</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] 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>