Jump at the onset of saltation

TL;DR

This paper demonstrates a discontinuous transition in the saturated flux of aeolian saltation through explicit particle motion simulations, revealing complex flow behaviors and a new flux-wind strength relationship.

Contribution

It introduces a novel simulation approach showing a discontinuous flux transition and coexistence of metastable states in aeolian saltation.

Findings

Discontinuous transition in saturated flux.

Existence of two metastable solutions.

Modified wind profile with a second maximum.

Abstract

We reveal a discontinuous transition in the saturated flux for aeolian saltation by simulating explicitly particle motion in turbulent flow. The discontinuity is followed by a coexistence interval with two metastable solutions. The modification of the wind profile due to momentum exchange exhibits a second maximum at high shear strength. The saturated flux depends on the strength of the wind as $q_s=q_0+A(u_*-u_t)(u_*^2+u_t^2)$.