Dynamics of secondary airflow and sediment transport over and in the lee of transverse dunes

Abstract: Recent research literature on secondary airflow and sediment transport patterns over flow-transverse dunes is reviewed. Various issues surrounding the behaviour, modelling and sedimentological implications of near-surface airflow dynamics over dunes are discussed, including: the Law of the Wall; the Jackson and Hunt airflow model; the effects of streamline compression, acceleration and curvature on stoss slope shear stress; and, in particular, recent efforts to characterize secondary lee-side airflow patterns. A revised conceptual model of lee-side airflow is presented and areas for further research are identified regarding the implications of such patterns for dune sedimentary dynamics, morphology, and migration. Key words: aeolian processes; boundary layer; lee-side airflow; sand dune dynamics; secondary airflow; sediment transport; shear stress; turbulence; wind tunnel simulation; wind velocity.