Further Studies on the Meteorology of West and Central Africa

Florida State University, Tallahassee FL

Investigators

Abstract

The PI will continue her investigations on interannual and interdecadal climate variability over tropical Africa. The focus is on west Africa, both the Sahel and Guinea Coast regions, and on equatorial Central Africa, a region where meteorological processes contributing to climatic variability are poorly understood. The study has an observational component, relying on past experience in observational analysis and the compilation of extensive data sets for West Africa, as well as a modeling component limited mainly to linear dynamical models. The PI suggests a new paradigm for understanding interannual and interdecadal variability in Sahelian Africa involving the latitudinal position of the African Easterly Jet (AEJ) and the role of the equatorial westerlies in displacing the jet northward into the Sahel region. Some of the key related questions to be addressed are (i) reasons for the shift in the AEJ; (ii) reasons for the development of deep equatorial Westerly jet in the monsoon flow over west Africa; and (iii) contrasts in the dynamics and energetics in the two stable modes of the jet. The role of the Tropical Easterly Jet, the Inter Tropical Convergence Zone, the moist layer and Easterly wave activity in interannual rainfall variability will also be studied. The work is important because better understanding of climate variability over this region will lead to better predictability of rainfall, and this has important societal benefits.