Variability of microphysical characteristics in the “21·7” Henan extremely heavy rainfall event  

作　　者：Gang CHEN Kun ZHAO Yinghui LU Yuanyuan ZHENG Ming XUE Zhe-Min TAN Xin XU Hao HUANG Haonan CHEN Fen XU Ji YANG Shushi ZHANG Xueqi FAN 

机构地区：[1]Key Laboratory of Transportation Meteorology of China Meteorological Administration,Nanjing Joint Institute for Atmospheric Sciences,Nanjing 210041,China [2]Key Laboratory for Mesoscale Severe Weather/MOE and School of Atmospheric Science,Nanjing University,Nanjing 210023,China [3]State Key Laboratory of Severe Weather and Joint Center for Atmospheric Radar Research of CMA/NJU,Chinese Academy of Meteorological Sciences,Beijing 100081,China [4]Center for Analysis and Prediction of Storms and School of Meteorology,University of Oklahoma,Norman,Oklahoma 73072,USA [5]Colorado State University,Fort Collins,CO 80523,USA

出　　处：《Science China Earth Sciences》2022年第10期1861-1878,共18页中国科学（地球科学英文版）

基　　金：jointly supported by the National Natural Science Foundation of China (Grant Nos. 42025501, 42005009, 41875053, U2142203);the National Key Research and Development Program of China (Grant No. 2017YFC1501703);the Basic Research Fund of CAMS (Grant No. 2021Z003);the Open Research Program of the State Key Laboratory of Severe Weather (Grant No. 2020LASW-A01)。

摘　　要：In this study, significant rainfall microphysical variability is revealed for the extremely heavy rainfall event over Henan Province in July 2021(the “21·7” Henan EHR event) using a dense network of disdrometers and two polarimetric radars.The broad distributions of specific drop size distribution(DSD) parameters are identified in heavy rainfall from the disdrometer observations, indicating obvious microphysical variability on the surface. A K-means clustering algorithm is adopted to objectively classify the disdrometer datasets into separate groups, and distinct DSD characteristics are found among these heavy rainfall groups. Combined with the supporting microphysical structures obtained through radar observations, comprehensive microphysical features of the DSD groups are derived. An extreme rainfall group is dominantly formed in the deep convection over the plain regions, where the high number of concentrations and large mean sizes of surface raindrops are underpinned by both active ice-phase processes and efficient warm-rain collision-coalescence processes in the vertical direction. Convection located near orographic regions is characterized by restricted ice-phase processes and high coalescence efficiency of liquid hydrometeors, causing the dominant DSD group to comprise negligible large raindrops. Multiple DSD groups can coexist within certain precipitation episodes at the disdrometer stations, indicating the potential microphysical variability during the passage of convective system on the plain regions.

关 键 词：The“21·7”Henan EHR event Microphysical characteristics VARIABILITY DISDROMETER Polarimetric radar 

分 类 号：P426.62[天文地球—大气科学及气象学]