Reconstructing martian winds at potential future landing sites with a regional lander network

Human missions to Mars will require detailed knowledge of local meteorological conditions. Continuous measurement of winds in the vicinity of a landing site is needed to provide accurate local weather monitoring and forecasting, thus preparing future expeditions to safeguard against the operational impact of hazardous dust events. These measurements are also required to ensure compliance with COSPAR planetary protection requirements regarding potential contamination of ‘special regions’ within the human exploration zone through the atmospheric transport of contaminants from human activities.

Key to understanding this local-scale atmospheric transport will be obtaining accurate measurements of the 3-D wind vector, most likely through a network of landers equipped with meteorological instrumentation. Here we build on a prior ESA internal study on a Mars Weather Network Mission to present an analysis of wind variability and reconstruction across six test-case landing sites - Chryse Planitia, Gusev and Schiaparelli craters, Mesopotamia, Mawrth Vallis and Hypanis Vallis - which have been proposed as future human exploration zones.

Local winds were simulated using the Laboratoire de Météorologie Dynamique Mars Mesoscale Model (Figure 1). An Empirical Orthogonal Function analysis was then performed, which decomposed the near-surface wind into orthogonal spatial patterns (EOFs). We found that the first 4 EOFs captured between 70-90% of wind variability at most sites.

By simulating continuous wind measurements from a network of four landers, we then calculated reconstructions of both the horizontal near-surface wind field as well as the full 3-D wind field for the first five kilometres above the surface. We found that Hypanis Vallis and Mesopotamia were the sites with the lowest reconstruction errors, and that reconstruction was poorer at sites with greater topographic variation such as the Gusev and Schiaparelli craters.

Our results provide the first quantification of wind field reconstruction error for meteorological monitoring using a network of landers on the Martian surface and therefore constitute a useful benchmark for future work. 

Figure 1 - Sample simulation output of the 3-D wind field at Chryse Planitia. The wind field has been visualised by initialising 1,000 particles at random locations, then using a Lagrangian trajectory algorithm to calculate how the particles are advected by the wind field. Particles are coloured by wind speed.