By using the data from an optical disdrometer,sounding and meteorological elements observed by Weining observation site in northwestern Guizhou in January 2014,the meteorological conditions,droplets characteristics and raindrop size distribution of the freezing precipitation were analyzed,and compared with the freezing precipitation in other southern cities of China.Results show that:(1) during the freezing precipitation events,the dominate synoptic system was quasi-stationary front,and the inversion existed in troposphere.The cloud thickness was thin and the cloud base was low.The near-surface temperature was below 0℃,relative humidity was above 85％,and the wind speed was low.(2) All freezing precipitation events were freezing drizzle,whose average diameter was 0.37mm and average rain intensity was 0.02mm.The liquid water content was highly correlated with the number concentration.The fitting result of raindrop size distribution shows Γ distribution was better than the M-P distribution.(3) Compared to other regions of southern China,Weining had smaller raindrops,weaker rain intensity and narrower spectra.(4) The freezing precipitation events in Weining took place through "super cooled warm rain" process,and the Yunnan-Guizhou quasi-stationary front and the high altitude mountainous terrain was likely responsible for the droplets characteristics.
Freezing precipitationMicrophysics characteristicsDroplet size distributionsSuper cooled warm rain process
国家科技期刊平台
NSTL
万方数据
维普
