Effect of a Change of the Surface Albedo of the Sahel on Climate

Abstract We have investigated with our general circulation model the effect of an increase of surface albedo over the Sahel on climate. When albedo increases, the precipitation and evaporation rates are lower. Our experiment also has shown variations of zonal circulation over the Sahel: the Tropical Easterly Jet is stronger and easterlies at low altitude are weaker when the precipitation rate is higher. These results, in agreement with observations of the changes of circulation between dry and wet years, suggest that the albedo can play an important role in the triggering or the maintenance of a drought in the Sahel through the effects of circulation.