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 lateral invariance and do not stop growing. Hence, simulations of two dimensional dune fields have been performed. Characteristic laws we...

The Dark UNiverse Explorer (DUNE) is a wide-field imaging mission concept whose primary goal is the study of dark energy and dark matter with unprecedented precision. To this end, DUNE is optimised for weak gravitational lensing, and also uses complementary cosmological probes, such as baryonic oscillations, the integrated Sachs-Wolf effect, and cluster counts. Immediate additional goals concer...

The engineering interest about dune fields is dictated by the their interaction with a number of human infrastructures in arid environments. Sand dunes dynamics is dictated by wind and its ability to induce sand erosion, transport and deposition. A deep understanding of dune aerodynamics serves then to ground effective strategies for the protection of human infrastructures from sand, the so-cal...

Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface-atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential ...

Large dune fields can overrun for instance infrastructures lying in the way of their motion. Unidirectional wind fields and low sand availability give rise to single barchan dunes moving in the direction of wind. They can interact by directly exchanging their sand through collisions. This kind of interaction plays a crucial role in the evolution of barchan dune fields, for instance on the selec...

Avalanche (grainflow) processes are fundamental drivers of dune morphodynamics and are typically initiated by grainfall accumulations. In sedimentary systems, however, the dynamism between grainfall and grainflow remains unspecified because simple measurements are hampered by the inherent instability of lee slopes. Here, for the first time, terrestrial laser scanning is used to quantify key asp...

The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show, by means of numerical simulations, 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...

We discuss the implementation of hybrid finite element methods in the Distributed and Unified Numerics Environment (DUNE). Such hybrid methods require the approximation of the solution in the interior of the elements, as well as an approximation of the traces of the solution on the element interfaces, i.e., the skeleton. For illustration, we consider a hybrid version of the interior penalty dis...

Sand dunes are often covered by vegetation and biogenic crusts. Despite their significant role in dune stabilization, biogenic crusts have rarely been considered in model studies of dune dynamics. Using a simple model, we study the existence and stability ranges of different dune-cover states along gradients of rainfall and wind power. Two ranges of alternative stable states are identified: fix...

We describe a search-based map generator for the classic real-time strategy game Dune 2. The generator is capable of creating playable maps in seconds, which can be used with a partial recreation of Dune 2 that has been implemented using the Strategy Game Description Language. Map genotypes are represented as low-resolution matrices, which are then converted to higher-resolution maps through a ...