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arXiv · 1202.2842

Linear stability analysis of transverse dunes

Hygor P. M. Melo·Eric J. R. Parteli·José S. Andrade Jr·Hans J. Herrmann
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Abstract

Sand-moving winds blowing from a constant direction in an area of high sand availability form transverse dunes, which have a fixed profile in the direction orthogonal to the wind. Here we show, by means of a linear stability analysis, that transverse dunes are intrinsically unstable. Any along-axis perturbation on a transverse dune amplify in the course of dune migration due to the combined effect of two main factors, namely: the lateral transport through avalanches along the dune's slip-face, and the scaling of dune migration velocity with the inverse of the dune height. Our calculations provide a quantitative explanation for recent observations from experiments and numerical simulations, which showed that transverse dunes moving on the bedrock cannot exist in a stable form and decay into a chain of crescent-shaped barchans.

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Hygor P. M. Melo, Eric J. R. Parteli, José S. Andrade Jr, Hans J. Herrmann. 2012-02-16. Linear stability analysis of transverse dunes. https://doi.org/10.1016/j.physa.2012.05.042

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