Modelling transverse dunes

TL;DR

This paper extends a dune model to two dimensions to simulate the dynamics and morphology of transverse dunes, revealing characteristic laws, modified Bagnold's law, and dune interactions such as smaller dunes passing larger ones.

Contribution

It introduces a two-dimensional shear stress calculation in dune modeling and explores dune interactions and growth behaviors not previously detailed.

Findings

Dune velocity follows a modified Bagnold's law.

Transverse dunes reach translational invariance and grow continuously.

Small dunes can pass through larger dunes during interactions.

Abstract

Transverse dunes appear in regions of mainly unidirectional wind and high sand availability. A dune model is extended to two dimensional calculation of the shear stress. It is applied to simulate dynamics and morphology of transverse dunes which seem to reach translational invariance and do not stop growing. Hence, simulations of two dimensional dune fields have been performed. Characteristic laws were found for the time evolution of transverse dunes. Bagnold's law of the dune velocity is modified and reproduced. The interaction between transverse dunes led to interesting results which conclude that small dunes can pass through bigger ones.