Robin Simons

Dynamics of Aeolian Sand Ripples

Abstract: We have simplified and extended the model of Hoyle and Mehta (1999) to three dimensions. This model describes the behaviour of aeolian sand ripples. It is a two-species model consisting of an upper layer of highly mobile grains and a lower layer of relatively immobile clusters. It also incorporates the effects of avalanching and transfer between the two species.

We calculate analytically the initial growth rate and preferred wavelength. The model is integrated numerically to show how ripples evolve over time. This is done using an univariate normal/gamma distribution to describe the joint probability distribution of the hop lengths.

Reference: R.B Hoyle and A.Mehta, Phys. Rev. Lett., vol. 83, p. 5170 (1999).