Dynamics of Convective Organization in African Easterly Waves observed during the NAMMA and CPEX-CV field experiments

Predicting tropical moist convection remains a challenging task. It is not fully understood how the fundamental ingredients of convective plumes produce organized tropical convection, particularly in weakly-rotating flows. In this study we aim to understand the dynamical processes that govern the convective organization, location, and intensity of convection in weakly rotating flows using NASA airborne field campaign and satellite observations. Data from twenty research flights into African easterly waves (AEWs) during the NASA African Monsoon Multidisciplinary Analysis (NAMMA) in 2006, and the Convective Processes Experiment- Cabo Verde (CPEX-CV) in 2022, were examined. We investigate the magnitude, spatial distribution, and variability of the potential vorticity, moisture, and vertical wind shear of the tropical disturbances using a 3D variational analysis technique called SAMURAI that integrates ERA5 reanalysis and the research aircraft observations. Furthermore, we classify convection from satellite imagery into shallow, medium, and deep occurrences, and obtain a statistical representation of the occurrence relative to the analyzed structure of the AEWs. The results show that around 50% of the time in the analyzed cases, deep convection is present in the southwest quadrant of the disturbance and is collocated with strong potential vorticity and high moisture. The implications of this research for improved understanding and prediction of tropical precipitation and tropical cyclogenesis will be discussed.