Presentation #203.07 in the session “Mars: Dust, Dynamics, and Dunes”.
On mars, the dust cycle is a critical factor that drives the weather and climate of the planet. Airborne dust affects the absorption and reflection of the solar radiation, directly affecting the energy balance that drives the atmospheric dynamic of the planet. In turn, the atmospheric dynamics influences the distribution of the dust particles, thus setting up a complex feedback. Therefore, for studying the present-day and recent-past climate of Mars we need to observe and understand the different processes involved in the dust cycle. To this end, the Mars Environmental Dynamics Analyser (MEDA) station includes a set of sensors (e.g. RDS or TIRS) capable to measure the radiance fluxes over the Martian surface. Combining these observations with radiative transfer (RT) simulations, airborne dust particles can be detected and characterized (optical depth, particle size, refractive index) along the day. The retrieval of these dust properties allows us to analyse the dust storms or dust lifting events, such as dust devils, on Mars.
Dust devils are thought to account for the ~50 % of the total dust budget, and they represent a continuous source of lifted dust, active even outside the dust storms season. For these reasons they have been proposed as the main mechanism able to sustain the ever-observed dust haze of the Martian atmosphere. Our radiative transfer simulations indicate that variations in the dust loading near the surface can be detected and characterized by MEDA radiance sensors [1,2]. During the first 100 sols the Radiation and Dust Sensor (RDS) has revelated a number of events (e.g. sharp variations in its signals) that are associated with the presence of dust devils. In this work we will present: i) the dust devil occurrence at Jezero as observed by RDS; ii) the characterization and validation of these events through radiative transfer simulations; and iii) the possible correlation between the observed dust lifting activity with short-time variations in the background optical depth.
References:  Apéstigue et al. (2015) EPSC, Nantes (France).  Rodríguez-Manfredi et al., special Mars2020 issue on SRR