Testing a new model of local wind erosion and dust deposition on field campaign data in Morocco. Adaptation of the model for Mars

Abstract

Global and mesoscale models represent the background (slowly varying) winds on Mars, but short timescale wind variability is not explicitly represented. The local wind erosion and dust deposition model can be useful for more accurate local wind friction, wind friction threshold, horizontal sand flux and vertical dust flux modeling on Mars. Such a model based on the model of Zender \cite{Zender} is proposed in this article. It includes different methods of threshold wind friction estimation and takes into account the influence of atmospheric electric fields on sand and dust elevation processes. The model parameterized for the Earth was tested on data acquired in Morocco field campaign 2013-2014 (Esposito et al.,) \cite{Esposito}, \cite{Esposito2}. Wind friction, wind friction threshold, horizontal sand flux and vertical dust flux were simulated by using the following inputs measured in the field: wind speed, wind direction, air temperature, air pressure, air humidity, solar irradiation and surface roughness length. The same inputs are supposed to be measured by DREAMs equipment on Mars (except for the surface roughness length which can be estimated for Mars according the method of Hebrard \cite{Hebrard}). Simulated and experimental values have shown a good agreement. The model was adapted to Martian conditions and applied to the data of Viking lander. The local wind erosion and dust deposition model parameterized for Mars may serve 1) to analyze local lander/rovers data, 2) a source of local parameters/inputs (like threshold wind friction velocity, sand and dust fluxes) for the MGCM (Mars Global Circulation Model).