Dune formation on the present Mars

TL;DR

This study models Martian dune formation under current atmospheric conditions, revealing that higher wind efficiency is necessary for dune creation and providing estimates for wind speeds, dune migration, and wind regime changes on Mars.

Contribution

It introduces a model for Martian dune formation that accounts for current atmospheric conditions and wind efficiency, offering new insights into Martian aeolian processes.

Findings

Martian dunes can form with current wind conditions if wind efficiency is higher.

Estimated wind speeds and dune migration velocities vary across Mars.

The timescale of wind regime changes on Mars is inferred from dune shape analysis.

Abstract

We apply a model for sand dunes to calculate formation of dunes on Mars under the present Martian atmospheric conditions. We find that different dune shapes as those imaged by Mars Global Surveyor could have been formed by the action of sand-moving winds occuring on today's Mars. Our calculations show, however, that Martian dunes could be only formed due to the higher efficiency of Martian winds in carrying grains into saltation. The model equations are solved to study saltation transport under different atmospheric conditions valid for Mars. We obtain an estimate for the wind speed and migration velocity of barchan dunes at different places on Mars. From comparison with the shape of bimodal sand dunes, we find an estimate for the timescale of the changes in Martian wind regimes.