Surface moisture feedback in modelled aeolian rippled sand strip and dune field patterns

Surface moisture plays a key role in controlling sediment availability and transport in aeolian systems which leads to the development of a diverse range of spatial patterns including transient sand strips on beaches with small temporal and spatial scales, and large-scale dune patterns dominated by wet interdune areas. By altering feedback response times between surface moisture and transport dynamics, these different patterns can be explored and modelled using a cellular automaton-based algorithm. This algorithm includes stochastic transport and mimics real-world behaviour, where surface moisture limits aeolian erosion, but a modest amount of moisture hardens the surface, increasing the elasticity of rebounding grains. Simulations allow for examination of different sediment availability scenarios which can be related to the developed internal stratigraphy of the modeled landscape. Results elucidate the controlling mechanism of surface moisture in sediment availability and highlight the importance of mutual feedback for developing diverse aeolian landscape patterns at different spatial and temporal scales.