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Abstract This study addresses the global distribution of precipitation mean particle size using data from the Global Precipitation Measurement (GPM) mission. The mass-weighted mean diameter, D m , is a characteristic parameter of the precipitation particle size distribution (PSD), estimated from the GPM Combined Radar-Radiometer Algorithm (CORRA) using data from GPM’s dual-frequency precipitation radar and microwave imager. We examine D m in individual precipitation systems in different climate regimes and investigate a six-year (2014-2020) global climatology within 70° N/S. The vertical structure of D m is demonstrated with cases of deep convection, frontal rain and snow, and stratocumulus light rain. The D m values, detectable by GPM, range from ~0.7 mm in stratocumulus precipitation to >3.5 mm in the ice layers of intense convection. Within the constraint of the 12-dBZ detectability threshold, the smallest annual mean D m (~ 0.8 mm) are found in the eastern oceans, and the largest values (~ 2 mm) occur above the melting levels in convection over land in summer. The standard deviation of the annual mean is generally < 0.45 mm below 6 km. Climate regimes are characterized with D m annual/seasonal variations, its convective/stratiform components, and vertical variabilities (2-10 km). The US Central Plains and Argentina are associated with the largest D m in a deep layer. Tropical Africa has larger D m and standard deviation than Amazon. Large convective D m occurs at high latitudes of Eurasia and North America in summer; the southern hemisphere high latitudes have shallower systems with smaller D m . Oceanic storm tracks in both hemispheres have relatively large D m , particularly for convective D m in winter. Relatively small D m occurs over tropical oceans, including ITCZ, requiring further investigation.
Han et al. (Wed,) studied this question.