Effects of Covering Layer of Sand Particles on Particle‐Bed Collision and Aeolian Sand Transport

Abstract

The effect of near-surface wind on sand particles is an important process that affects substance transport, landform evolution, and climate change on Earth, Mars, and other terrestrial planets (Bagnold, 1941;Kroy et al., 2002;Shao, 2008). On a smaller scale, saltation of sand particles is a direct driving factor for the erosion of dunes and the release of dust on the surface (Bagnold, 1935;Diniega et al., 2017). Saltation can be divided into four physical processes-the surface particles are triggered by aerodynamic lift; the particles are accelerated by the wind to move in a ballistic trajectory; the falling particles impact the sand bed surface, and at the same time of rebounding, they agitate new sand particles to leave the bed surface, thus, creating a chain reaction; the saltation particles modify the wind speed profile by exerting a drag force. Aeolian sand transport models based on these four processes have been widely used in computer simulations of two-phase aeolian-sand flows on the