Abstract ATM-9807068 Eltahir, Elfatih Massachusetts Institute of Technology Title: The Role of the Distribution of SST and Vegetation in Rainfall Variability Over West Africa The request of $342,383/36 months is to examine the hypothesis that the rainfall variability over West Africa is regulated by the meridional gradient of boundary layer conditions (entropy or moist static energy). The influence of both vegetation distribution over land and SST variation over the tropical Atlantic ocean on the meridional gradient of the boundary layer will be examined. Both historical data and numerical models will be utilized for the study. The study is important since understanding monsoon variability over west Africa will help better predict droughts, floods; all this has high potential societal impacts.