Diagnosis of the Kinetic Energy of the“21·7”Extreme Torrential Rainfall Event in Henan Province,China  

作　　者：Xiuping YAO Ruoying LI Xiaohong BAO Qiaohua LIU 

机构地区：[1]China Meteorological Administration Training Centre,Beijing 100081,China [2]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China [3]College of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,China

出　　处：《Advances in Atmospheric Sciences》2024年第1期73-83,共11页大气科学进展（英文版）

基　　金：jointly supported by the National Natural Science Foundation of China(Grant Nos.42275013,42030611 and 42175008);the Open Grants of the State Key Laboratory of Severe Weather(Grant No.2021LASWB17)。

摘　　要：An extreme torrential rain(ETR)event occurred in Henan Province,China,during 18-21 July 2021.Based on hourly rain-gauge observations and ERA5 reanalysis data,the ETR was studied from the perspective of kinetic energy(K),which can be divided into rotational wind(V_(R))kinetic energy(K_(R)),divergent wind kinetic energy(K_(D)),and the kinetic energy of the interaction between the divergent and rotational winds(K_(RD)).According to the hourly precipitation intensity variability,the ETR process was divided into an initial stage,a rapid increase stage,and maintenance stage.Results showed that the intensification and maintenance of ETR were closely related to the upper-level K,and most closely related to the upperlevel K_(R),with a correlation coefficient of up to 0.9.In particular,the peak value of hourly rainfall intensity lagged behind the K_(R) by 8 h.Furthermore,diagnosis showed that K transformation from unresolvable to resolvable scales made the ETR increase slowly.The meridional rotational wind(u_(R))and meridional gradient of the geopotential(φ)jointly determined the conversion of available potential energy(APE)to K_(R) through the barotropic process,which dominated the rapid enhancement of K_(R) and then caused the rapid increase in ETR.The transportation of K by rotational wind consumed K_(R),and basically offset the K_(R) produced by the barotropic process,which basically kept K_(R) stable at a high value,thus maintaining the ETR.

关 键 词：extreme torrential rain rotational kinetic energy kinetic energy generation and transport barotropic process 

分 类 号：F42[经济管理—产业经济]