0019-1035/$ see front matter 2009 Elsevier Inc. A doi:10.1016/j.icarus.2009.08.023 * Address: Planetary Science Institute, 1700 E. Ft. Lo USA. Fax: +1 520 795 3697. E-mail address: [email protected]. Barchan dune asymmetry refers to the extension of one barchan limb downwind. It is a common dune form on Earth and also occurs on Mars and Titan. A new classification of barchan limbs is presented wh...

Corridors of size-selected crescent-shaped dunes, known as barchans, are commonly found in water, air, and other planetary environments. The growth barchans results from the interplay between a fluid flow granular bed, but their size regulation involves intricate exchanges different within field. One size-regulating mechanism is binary interaction nearby when two dunes exchange mass via near fi...

Introduction: Barchans are individual, mobile, crescentic shape dunes, the two horns of which face in the direction of movement. Generally they occur in areas of limited sand supply, with a low precipitation and vegetation cover, on planar surfaces and where winds are unimodal to narrowly bimodal. On Mars, the most common dune is transverse and within the barchan group there is a wide variety o...

Sand dunes are found in a wide variety of shapes in deserts and coasts, and also on the planet Mars. The basic mechanisms of dune formation could be incorporated into a continuum saltation model, which successfully reproduced the shape of the barchan dunes and has been also applied to calculate interaction of barchans in a field. We have recently extended our dune model to investigate other dun...

Many dune fields exhibit a downwind transition from forward-pointing barchan dunes to stabilized, backward-pointing parabolic dunes, accompanied by an increase in vegetation. A recent model predicts this pattern transition occurs when dune surface erosion/deposition rates decrease below a threshold of half the vegetation growth rate. We provide a direct test using a unique data set of repeat to...

Barchan dunes, or simply barchans, are crescent-shaped dunes found in diverse environments such as the bottom of rivers, Earth's deserts and surface Mars. In a recent paper [Phys. Rev. E 101, 012905 (2020)], we investigated evolution subaqueous barchans by using computational fluid dynamics - discrete element method (CFD-DEM), our simulations captured well an initial pile toward barchan dune bo...

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...

Barchan dunes are found where sand availability is low and wind direction quite constant. The two dimensional shear stress of the wind field and the sand movement by saltation and avalanches over a barchan dune are simulated. The model with one dimensional shear stress is extended including surface diffusion and lateral shear stress. The resulting final shape is compared to the results of the m...

0019-1035/$ see front matter 2011 Elsevier Inc. A doi:10.1016/j.icarus.2011.01.005 ⇑ Corresponding author. Fax: +33 4 72 44 85 93. E-mail address: [email protected] (E. Ga High albedo features are identified in association with barchan dunes in an equatorial inter-crater dune field on Mars using images from the MRO mission. This paper describes the morphometric properties of these fea...