Characterisation of dust events on Earth and Mars: the ExoMars/DREAMS experiment and the field campaigns in the Sahara desert

TL;DR

This study compares dust lifting phenomena on Earth and Mars by analyzing Sahara desert campaigns and data from the ExoMars missions, providing insights into dust dynamics and electric properties relevant for future Mars exploration.

Contribution

It presents the first comprehensive dataset of synchronous meteorological, electric, and dust measurements during dust events in the Sahara, aiding the understanding of Martian dust processes.

Findings

First synchronous measurements of dust, electric field, and meteorology during Sahara dust events.

Indications of the relationship between electric fields and dust grain suspension.

Comparison of terrestrial dust activity with Martian data for future mission analysis.

Abstract

Atmospheric dust plays an important role on the terrestrial climate, regulating the amount of solar radiation coming to the surface, affecting the development and the life time of the clouds and providing fundamental nutrients to the growth of the terrestrial and oceanic biomes. On Mars, the global effect of dust is even stronger due to the widespread presence of sources and the lack of vegetation and oceans able to mitigate its contribution. The DREAMS station and the Dust Complex, on board of the ExoMars 2016 and 2020 mission respectively, have been specifically developed for the study of the Martian airborne dust. During my Phd I joined the team that lead the DREAMS experiment and the MicroMed sensor of the Dust Complex. As a part of the instruments developing and the acquisition of martian analogous data, our team has carried out various campaigns in the Sahara desert, to study the environment and the lifting phenomena that are expected on Mars. We monitored the dust lifting events by acquiring, for the first time in literature, synchronous measurement of meteorological data, atmospheric electric field, saltation activity and suspended dust concentration. Currently, this is the most complete data set available for the study of the dust lifting processes. We worked on the development of proper detection algorithms to individuate the dust events acquired in the surveys, applicable also to the future martian missions. We studied the characteristic of the observed dust storm and dust devils activity, focusing on their electric proprieties. In particular, we obtained the first experimental indications of how the induced electric field is related to the amount of suspended grains and meteorological characteristics of the events. We compared the terrestrial results with the currently available martian data, in order to prepare the analysis of the next ExoMars measurements.