Multi-sensor satellite remote sensing of dust aerosols over North Africa during GERBILS

In this paper we provide an overview of various satellite products over the Sahara Desert that were available during the GERBILS field campaign. Our results indicate that all mid-visible satellite aerosol optical depth (AOD) products match well with AERONET retrievals. For low AOD (AOD < 1), the satellite AODs compare well with aircraft AOD values but they tend to underestimate at high AOD values. We then assessed the satellite products in 0.5 x 0.5 degree grids for the entire study region (10-30 degrees N and 20 degrees W-10 degrees E). If we use a multi-angle imaging spectroradiometer (MISR) as a benchmark for AOD retrievals over bright targets, the estimated AOD derived from the ozone-monitoring instrument aerosol index-MISR relationship performs best when compared with MISR for the entire study region. Although differences exist among satellite products, the advancement in satellite retrieval techniques now provide AOD retrievals over bright targets such as deserts, which are useful for numerical modeling simulation comparisons and other studies. Furthermore, the in situ information from aircraft and the ground continue to provide valuable information for validating satellite products and for assessing their strengths and weaknesses. Copyright (C) 2011 Royal Meteorological Society and British Crown Copyright, the Met Office