Global Distribution of Three Types of Drop Size Distribution Representing Heavy Rainfall From GPM/DPR Measurements

Abstract

In this study, Gaussian mixture model clustering analysis was carried out to examine characteristics of Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR)-retrieved mass-weighted mean diameter (Dm), and normalized intercept parameter (Nw) of the drop size distribution (DSD) for heavy rainfalls (>10 mm h−1) for 6 years (2014–2019). Three objective DSD types – continental, oceanic deep, and oceanic shallow convective types – emerged. The means and standard deviations of Dm and Nw obtained for the three types are in good agreement with various ground-based observations, indicating that global view of DSD characteristics can be obtained from DPR-derived DSD parameters. Global distributions of occurrence and contribution of each DSD type to total heavy rainfall are produced for the first time, which will help examine the dominant DSD type, its contribution to total heavy rainfall, and composition of different convective types in the rainfall system at a given location.