Retrieval of martian dust and cloud properties from ground-based radiance dust sensors

On Mars, dust and clouds are primary elements for studying the interactions of solar radiation with the atmosphere and surface and their influence on the radiation balance. Depending on the dust opacity and other properties such as the particle size distribution, airborne dust can provide positive or negative radiative feedbacks into dynamical processes. This role played by dust in the circulation of the atmosphere points out the need of retrieving the dust optical properties at different time periods and locations. In order to perform these observations a number of ground-based radiance dust sensors were selected for Exomars and Mars 2020 missions (e.g. Arruego et al., Advances in Space Research, 60, 2016; Apéstigue et al., EPSC 2015). These instruments measure the solar flux at different wavelengths and sky locations along the day. From radiative transfer simulations of these observations, dust properties such as the number density or particles radius can be inferred. In this work, we will present and discuss different retrieval procedures developed for the characterization of dust and clouds on Mars.