Difference in the wind speeds required for initiation versus continuation of sand transport on Mars: Implications for dunes and dust storms

TL;DR

This study reveals that on Mars, saltation can persist at wind speeds much lower than those needed to start it, due to a hysteresis effect, impacting our understanding of Martian dunes and dust storms.

Contribution

It demonstrates that saltation on Mars is maintained at lower wind speeds than initiation, highlighting a hysteresis effect with significant implications for Martian surface features.

Findings

Saltation can be sustained at wind speeds an order of magnitude lower than initiation.

Hysteresis causes saltation to occur at lower wind speeds than previously believed.

Implications for the formation of Martian dunes and dust storms.

Abstract

Much of the surface of Mars is covered by dunes, ripples, and other features formed by the blowing of sand by wind, known as saltation. In addition, saltation loads the atmosphere with dust aerosols, which dominate the Martian climate. We show here that saltation can be maintained on Mars by wind speeds an order of magnitude less than required to initiate it. We further show that the resulting hysteresis effect causes saltation to occur for much lower wind speeds than previously thought. These findings have important implications for the formation of dust storms, sand dunes, and ripples on Mars.