暴雨灾害 (Oct 2023)
Basic characteristics of monitoring global DPR Droplet Size Distribution and Precipitation Reflectivity Factor from June to August
Abstract
Obtaining monitoring global droplet size distribution (DSD) is of great scientific significance for the study of precipitation characteristics and has important applications in retrieving precipitation by precipitation radar. Based on the GPM data provided by NASA's Goddard Flight Center (GFSC) and ERA5 reanalysis data, three-dimensional structure of DPR-derived mass-weighted mean diameter (D0) and normalized intercept parameter (dBNw) of DSD and precipitation reflectivity factor (PRF) from June to August in 2014-2020 were investigated. The regional and sea-land differences of DSD parameters and PRF in different latitudinal zones were also analyzed. The results are as follows. The spatial distribution patterns of D0 and dBNw are different and the large value region of dBNw (> 35) has small D0 ( 1.2 mm). The mean D0 over the land surface is larger than that over the ocean, but the mean dBNw is smaller than that over the ocean, and there are great differences between land and sea in the tropics and the northern hemisphere. The vertical distribution of precipitation reflectivity factor (PRF) is mainly determined by D0, and dBNw is a secondary factor. The D0 mean profile indicates that the main microphysical processes of the large, medium, and small precipitation particles are different. The dBNw profile indicates that the concentration of mean particles in the upper layer is smaller than that in the lower layer. Compared with other terrestrial regions, the distributions of DSD parameters and PRF over the Tibetan Plateau are the most concentrated, and the precipitation particles are smaller in size and lower in concentration.
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