Comparative Analysis of the Characteristics of Rainy Season Raindrop Size Distributions in Two Typical Regions of the Tibetan Plateau  

作　　者：Gaili WANG Ran LI Jisong SUN Xiangde XU Renran ZHOU Liping LIU 

机构地区：[1]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Science,Beijing 100081,China

出　　处：《Advances in Atmospheric Sciences》2022年第7期1062-1078,共17页大气科学进展（英文版）

基　　金：the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0105);the National Natural Science Foundation of China(Grant No.41775036).

摘　　要：Mêdog and Nagqu are two typical regions of the Tibetan Plateau with different geographical locations and climate regimes.These differences may lead to discrepancies in the raindrop size distributions(DSDs)and precipitation microphysical processes between the two regions.This paper investigates discrepancies in the DSDs using disdrometer data obtained during the rainy season in Mêdog and Nagqu.The DSD characteristics are studied under five different rainfall rate categories and two precipitation types(stratiform and convective).For the total datasets,the number concentrations of drops with diameters D>0.6(D<0.6)mm are higher(lower)in Nagqu than in Mêdog.The fitted normalized gamma distributions of the averaged DSDs for the five rainfall rate categories show that Nagqu has a larger(lower)mass-weighted mean diameter D_(m)(normalized intercept parameter,lgNw)than Mêdog does.The difference in D_(m)between Nagqu and Mêdog increases with the rainfall rate.Convective clusters in Nagqu could be identified as continental-like,while convective precipitation in Mêdog could be classified as maritime-like.The relationships between the shape factorμand slope parameterΛof the gamma distribution model,the radar reflectivity Z,and the rainfall rate R are also derived.Furthermore,the possible causative mechanism for the notable DSD variation between the two regions during the rainy season is illustrated using reanalysis data and automated weather station observations.Cold rain processes are mainly responsible for the lower concentrations of larger drops observed in Nagqu,whereas warm rain prevails in Mêdog,producing abundant small drops.

关 键 词：raindrop size distribution Tibetan Plateau continental-like maritime-like warm rain cold rain 

分 类 号：P426.6[天文地球—大气科学及气象学]