Analysis of Raindrop Size Distribution of Precipitation During Flood Season in the Northern and Coastal Regions of South China Sea
HUANG Chaoying
CHEN Sheng
SUN Qibin
XIAN Xinghe
WANG Guozhang
CAI Yiping
MO Weiqiang
Abstract：This study analyzes the characteristics of raindrop size distribution in the coastal areas and the northern regions of the South China Sea during pre-and post-monsoon periods.The study utilizes one-dimensional observation data from the Yongxing Island Observatory in the South China Sea from 2020 to 2022,and from three stations including Zhuhai,Guangzhou,and Foshan in Guangdong Province from 2018 to 2022.The analysis includes the Dm-Nw distribution characteristics in different flood seasons,the variations of the particle size distribution with rainfall intensity and diurnal variations,and the μ-Λand Z-Rrelationships.The results show that,influenced by lower aerosol concentrations and higher evaporation rates over the ocean,the number concentration of small raindrops in oceanic flood season precipitation is lower than that in coastal precipitation.For a given rainfall intensity,when it is less than 10 mm·h-1,the fitted spectra of medium-sized raindrops in oceanic and coastal precipitation show almost consistent trends across pre-and post-flood season.However,with increasing rainfall intensity,the difference in number concentration of medium and large raindrops among different precipitation types gradually increases.The number of large raindrops in both coastal and oceanic precipitation is mainly concentrated in the evening and nighttime during the post-flood season.The μ-Λrelationships within the same region show similarity.As Λ increases,the μ values of coastal pre-and post-flood season precipitation show significant differences,with the μ value of post-flood season precipitation being larger than that of the pre-flood season.This indicates that the concentration of small raindrops in pre-flood season precipitation is lower than that in post-flood season precipitation,and the high concentration of small raindrops is the reason for the relatively small μ.Furthermore,significant differences exist in the Z-R relationships at different latitudes.The raindrop diameter and number concentration in coastal post-flood season precipitation are both larger than those in the pre-flood season,while these parameters in oceanic pre-and post-flood season precipitation are similar.
Keywords：raindrop size distributionflood season precipitationSouth China SeaZ-Rrelationship
Publication Date：2025-12-31
Online Publishing Date：2026-01-12(First online date of this platform, not the publication date of the document)
Pages：14( 833-846 )