Transverse instability of dunes
Soft Condensed Matter
2015-05-30 v1
Abstract
The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show numerically and with a linear stability analysis that transverse dunes are unstable with respect to along-axis perturbations in their profile and decay on the bedrock into barchan dunes. Any forcing modulation amplifies exponentially with growth rate determined by the dune turnover time. We estimate the distance covered by a transverse dune before fully decaying into barchans and identify the patterns produced by different types of perturbation.
Cite
@article{arxiv.1109.4822,
title = {Transverse instability of dunes},
author = {Eric J. R. Parteli and José S. Andrade and Hans J. Herrmann},
journal= {arXiv preprint arXiv:1109.4822},
year = {2015}
}
Comments
4 pages, 3 figures; To appear in Physical Review Letters