Evolution of the Vertical Structure of the Saharan Air Layer during the Land–Ocean Transition Using MERRA-2 Global Analyses and Nu-WRF Model Simulations

The Saharan air layer (SAL) is a warm, dry, and often dusty isentropic layer that results from the intense surface heating and dry convection over the Saharan Desert. The SAL is critical to the formation of both African easterly jet and African easterly waves, which directly impact the weather of northern Africa and downstream tropical cyclogenesis. Our investigation will characterize the structure of the SAL as represented in the NASA Modern Era Retrospective-analysis for Research and Applications (MERRA-2) global analyses with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) at 0.5°x0.625° grid resolution and in the NASA Unified WRF (NU-WRF) including real-time aerosol-cloud-radiation coupling with a 3x3 km grid resolution. Using these model data, we will investigate how the vertical structure (dust and thermodynamic properties) of the Saharan Air Layer evolves during its transit from northern Africa and into the eastern Atlantic.