Numerical Study on the Impacts of Hydrometeor Processes on the“21·7”Extreme Rainfall in Zhengzhou Area of China  

作　　者：Wenhua GAO Chengyin LI Lanzhi TANG 

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

出　　处：《Advances in Atmospheric Sciences》2024年第10期2061-2078,共18页大气科学进展（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42275082 and 41775131);the S&T Development Fund of CAMS(Grant No.2023KJ030).

摘　　要：The impacts of hydrometeor-related processes on the development and evolution of the“21·7”extremely heavy rainfall in Zhengzhou were investigated using WRF simulations.Surface precipitation was determined by the hydrometeor microphysical processes(all microphysical source sink terms of hydrometeors)and macrophysical processes(local change and flux convergence of hydrometeors).The contribution of hydrometeor macrophysical processes was commonly less than 10%,but could reach 30%–50%in the early stage of precipitation,which was largely dependent on the size of the study area.The macrophysical processes of liquid-phase hydrometeors always presented a promotional effect on rainfall,while the ice-phase hydrometeors played a negative role in the middle and later stages of precipitation.The distributions of microphysical latent heat corresponded well with those of buoyancy and vertical velocity(tendency),indicating that the phase-change heating was the major driver for convective development.Reasonable diagnostic buoyancy was obtained by choosing an area close to the convective size for getting the reference state of air.In addition,a new dynamic equilibrium involving hydrometeors with a tilted airflow was formed during the heavy precipitation period(updraft was not the strongest).The heaviest instantaneous precipitation was mainly produced by the warm-rain processes.Sensitivity experiments further pointed out that the uncertainty of latent heat parameterization(±20%)did not significantly affect the convective rainfall.While when the phase-change heating only altered the temperature tendency,its impact on precipitation was remarkable.The results of this study help to deepen our understanding of heavy rainfall mechanisms from the perspective of hydrometeor processes.

关 键 词：heavy precipitation hydrometeor processes BUOYANCY latent heat 

分 类 号：P461[天文地球—大气科学及气象学]