Statistical Characteristics of Raindrop Size Distribution in Beibu Gulf over Southern China

Abstract:

The raindrop size distributions (DSDs) observation is a key step for microphysical analysis of cloud and precipitation, which forms the basis for the development of microphysical parameterization schemes in numerical models. DSDs vary both spatially and temporally and even in different types of storm and weather system. Extreme precipitation events such as cold (winter) season rainstorm, strong convective weather during flood season and typhoon in southern China usually cause flash flood, urban waterflood, landslide, mountain torrents and other geological disasters in the coastal areas of Beibu Gulf. The statistical characteristics of DSDs from April to August 2020 are studied with observations from the second-generation Particle Size and Velocity (Parsivel2) disdrometer and new generation weather radar located in Beibu Gulf over southern China. The characteristics are quantified based on the DSDs parameters and polarimetric radar parameters retrieved by T-matrix and later analyzed with the raindrop spectra, characteristics of parameter variations with rainfall rate, and the relationships between reflectivity factor (Z) and rainfall rate (R), as well as their DSDs changes with precipitation type and rainfall rate. These timely useful feedbacks offer insights of the microphysical nature of precipitation in Guangxi during flood season, and provide essential information that may be useful for precipitation retrievals based on weather radar observations.