LINKING AEOLIAN BEDFORM MIGRATION TO WIND SPEED ON EARTH AND MARS (Invited Presentation)

Bringing new insights to interaction between wind and sand systems is critical in our understanding of aeolian dynamics on Earth and other bodies. Here, we present a workflow that quantitatively relates the rate of barchan dunes migration, which can be measured from remote sensing, to the wind velocity, either measured at a meteorological station or extracted from reanalysis data.

We validate this workflow using data from Earth and apply it on Mars. The workflow requires the selection of a sand transport law and a procedure to estimate the effect of the local topography on the near surface airflow, namely the speed-up effect. Additionally, the estimate of sand flux under natural conditions needs to account for short duration wind gusts which are usually not fully accounted for or sampled in climatic models. We investigate these effects by using computational fluid dynamic (CFD) modeling to estimate the speed-up effect on airflow and sand transport. We next include that effect to compare the predicted dune migration rate with remote sensing observations, at two desert barchan dune fields located along the southern rim of the Arabia Gulf. This workflow is then applied to a barchan dune fields on Mars.