The apparent roughness of a sand surface blown by wind from an analytical model of saltation

TL;DR

This paper introduces an analytical model for aeolian sand transport that accurately predicts saltation layer thickness, surface roughness, and sand flux, aligning well with experimental and simulation data, and applicable to Earth and Mars.

Contribution

The model provides a physically-based, simple analytical framework for predicting sand transport parameters, improving upon previous models by matching experimental results.

Findings

Predicted saltation layer thickness and surface roughness agree with experiments.

Model accurately estimates sand transport rate and impact threshold.

Applicable to aeolian processes on Earth and Mars.

Abstract

We present an analytical model of aeolian sand transport. The model quantifies the momentum transfer from the wind to the transported sand by providing expressions for the thickness of the saltation layer and the apparent surface roughness. These expressions are derived from basic physical principles and a small number of assumptions. The model further predicts the sand transport rate (mass flux) and the impact threshold (the smallest value of the wind shear velocity at which saltation can be sustained). We show that, in contrast to previous studies, the present model's predictions are in very good agreement with a range of experiments, as well as with numerical simulations of aeolian saltation. Because of its physical basis, we anticipate that our model will find application in studies of aeolian sand transport on both Earth and Mars.