An analytic study of the effect of saltation on wind profiles

An analytic study of wind profiles above the saltation layer. in which the motion of uniform saltating grains of sand or snow occurs. is conducted. In this study, analytic solutions of the Ekman layer equation that governs th e motion of air in a barotropic, neutral atmosphere are obtained in order t o investigate the effects of the saltation on the airflow at large distance from a smooth surface. Solutions are derived subject to expressions of the eddy viscosity K(z) defined above the saltation layer up to the Ekman laye r. The wind profiles and boundary layer interactions with the saltation pro cess are discussed. With the assumptions that the eddy viscosity varies smo othly from the surface layer to the Ekman layer and K = 0.4u*z(1 - z/h), th e solutions are found to be consistent with bottom boundary conditions, spe cified by the velocity profile law outside the saltation layer. These solut ions can be either used as an alternative to predict the saltation or used to test the sensitivities of the parameterization scheme designed to simula te dust emissions in a climate or general circulation model (GCM).