[1] Although evidence is mounting that links global warming to changes in atmospheric dynamics over the Atlantic realm, similar studies over the African continent are lacking. And even if such models would exist, it would be difficult to verify their validity due to the paucity of meteorological observations and anemometers in the central Sahara. A pragmatic way around this problem is to monito...

Introduction: THEMIS and MOC images acquired over the Chasma Boreale contain key geologic and stratigraphic information relating to aeolian deposition and the Polar Layered Deposits (PLD). Preliminary analyses of THEMIS VIS and MOC images show a clear progression of morphologic change of dark albedo dune deposits along the chasma axis. Geologic Relations: The source for the dunes appears to be ...

In this paper we present the new Dune-ALUGridmodule. This module contains a major overhaul of the sources from the ALUGrid library and the binding to the Dune software framework. The main improvements concern the parallel feature set of the library, including now user defined load balancing and parallel grid construction. In addition many improvements have been introduced into the code to incre...

We use FLUENT to calculate the wind profile over barchans and transverse dunes. The form of the streamlines of flow separation at the lee side of the dunes is determined for a symmetric barchan dune in three dimensions, and for the height profile of a measured transverse dune field in the Lençóis Maranhenses.

The trait-based approach shows that plant functional diversity strongly affects ecosystem properties. However, few empirical studies show the relationship between soil fungal diversity and plant functional diversity in natural ecosystems. We investigated soil fungal diversity along a restoration gradient of sandy grassland (mobile dune, semifixed dune, fixed dune, and grassland) in Horqin Sand ...

Eolian dune fields on Earth and Mars evolve as complex systems within a set of boundary conditions. A source-to-sink comparison indicates that although differences exist in sediment production and transport, the systems largely converge at the dune-flow and pattern-development levels, but again differ in modes of accumulation and preservation. On Earth, where winds frequently exceed threshold s...

Vegetation patterns are strongly influenced by sand mobility in desert ecosystems. However, little is known about the spatial patterns of Artemisia ordosica, a dominant shrub in the Mu Us desert of Northwest China, in relation to sand fixation. The aim of this study was to investigate and contrast the effects of sand dune stabilization on the population and spatial distribution of this desert s...

This thesis describes dune development on natural and nourished beaches on an engineering timescale. Using a study of both literature and data gathered from the Dutch coast, a new hypothesis regarding the causes of variability in dune evolution is proposed. Following this hypothesis assumptions are made on the basis of which a conceptual model is developed that includes both the accretive and e...

The spatio-temporal evolution of a downsized model for a desert dune is observed experimentally in a narrow water flow channel. A particle tracking method reveals that the migration speed of the model dune is one order of magnitude smaller than that of individual grains. In particular, the erosion rate consists of comparable contributions from creeping (low-energy) and saltating (high-energy) p...

In this contribution we describe and evaluate an efficient implementation of an adaptive and parallel grid (ALUGrid) within the Distributed and Unified Numerics Environment DUNE. A generalization of the serial grid interface of DUNE, described in [1], to the adaptive and parallel case is discussed and example computations using the grid interface are presented. The computations are compared wit...