Seasonal evolution of diabatic heating and associated meridional circulation over the West African Monsoon region

Tropical diabatic heating is found to be dominated by two vertical modes, one deep, one shallow. These two modes support very different vertical overturning circulations. Over the West African monsoon region, however, the surface temperature gradient drives a circulation pattern distinct from those associated with the two vertical modes of diabatic heating. This study compares the West African monsoon circulations related to the three driving factors and their potential effects on monsoon rainfall.