Investigate the Forcing Mechanisms Leading to the Formation of the African Easterly Waves Preceding the Genesis of Hurricanes in the Atlantic Ocean

African Easterly Waves (AEWs) are dominant synoptic-scale atmospheric disturbances that occur in Africa and the tropical north Atlantic during the summer. They often serve as precursors to the generation of hurricanes in the Atlantic Ocean. Thus, it is important to understand the origin of those AEWs, especially over eastern Africa. This study investigates the forcing mechanisms, such as the thermal and mechanical forcing, responsible for the formation of AEWs preceding the genesis of hurricanes in the Atlantic basin. Combining satellite observations, reanalysis data, and numerical model simulations using the Weather Research and Forecasting (WRF) model, several previous proposed mechanisms have been examined, including topographic influence, diabatic heating, and cyclonic vorticity induced by the convergence of northerly and southerly winds from the highs over the Arabian Peninsula and the Indian Ocean. The results show that the presence of substantial topography in eastern Africa, such as the Ethiopian Highlands and Darfur Mountains, plays a key role in the AEW formation through convective initiation produced by combined mechanical and thermal forcing in the region. The findings of this study provide important insights into the physical processes that govern the formation and evolution of the AEWs and their subsequent influence on the development of hurricanes in the Atlantic Ocean, which can be useful for improving seasonal forecasting and predicting the behavior of these storms.