Observations of tropical precipitating clouds ranging from shallow to deep convective systems

Abstract

Regional and temporal variability in a broad spectrum of tropical precipitation systems is investigated in conjunction with the large‐scale environment. The analysis utilizes four storm categories (Shallow, Cumulus Congestus, Deep Stratiform, and Deep Convective) determined from Tropical Rainfall Measuring Mission (TRMM) measurements. Deep Stratiform and Deep Convective systems are found to be clearly correlated with large‐scale circulation deduced from a reanalysis data set, and are modulated by a distinct seasonal cycle over land. The Shallow category is practically the only component of tropical oceanic rainfall for cold sea surfaces, while it gives way to deeper systems as SST exceeds 28–29°C. The cloud horizontal scale of organized rainfall systems tends to be increasingly extensive relative to the raining portion as the system becomes larger. The present results are discussed in light of existing relevant studies.