Three-dimensional structure of the Saharan Air Layer

It is well documented that the radiative effect of the Saharan Air Layer (SAL) with respect to regional and global climate is poorly understood. Spatial structures of the dust content and humidity of the SAL are crucial factors of its climatic impacts. The newly available data from the CALIPSO satellite on the A-Train constellation allows, for the first time, vertical aerosol profiling with aerosol and cloud type distinction. Based on the CALIPSO data, seasonal mean 3-D structures of the SAL are examined in terms of its aerosol type and total aerosol concentration. A well defined seasonal spatial structure exists over the eastern tropical Atlantic. In the western Atlantic, the cohesive structure diminishes, particularly in boreal winter. In addition, statistical examinations of aerosol layer altitude, thickness, and optical depth are exhibited.