Geospatial Distribution and Projection of Aerosol over Sub-Saharan Africa: Assessment from Remote Sensing and Other Platforms

Saharan Africa has experienced persistent exposure to aerosol from time immemorial, but the intensity has been much more severe in recent years. In this study, aerosol optical depths (AOD) retrievals from ground-based, satellite-based and modelled data set were compared, for the time scale of 1994–2019, 2000–2019, and 1985–2019, respectively, over Saharan Africa. Validation of satellite-based records and model aerosol records were complemented by ground-based records; also, seasonal variations in the atmospheric aerosol were predicted using multiple decadal projections. Results from the multi-model ensemble showed no significant differences between mean monthly aerosol retrieved from different platforms and model-based, where F = 55.114 for ground-based, F = 66.675 for satellite-based, F = 49.638 for the model data set, with Sig = 0.000 at P < 0.05. The study concludes that seasonal variation in Saharan Africa could be accounted for the variation in AOD and the Bodélé depression in Chad which mainly releases nearly 40% of the dust over parts of Saharan Africa especially during the harmattan.