Unraveling the Genesis of the 7.20 Zhengzhou Rainstorm:An Analysis with a Focus on Severe Convective Rain Cell Evolution
YANG Jiayan
LI Yunying
CHEN Zitong
Abstract：Under the joint influence of the relatively stronger and more northerly western Pacific subtropical high,intensified Typhoon In-Fa and the southwest monsoon,a heavy rainstorm struck Henan Province,China,on July 20,2021.The rainstorm event caused severe casualties and economic losses in many cities,with Zhengzhou being the worst-hit region.Based on the cloud-top brightness temperature data of the Himawari-8 satellite,this study used the iterative convective rain cell tracking algorithm to identify and track the main convective rain cells of the rainstorm event and explored the causes of the rainstorm.The results show that the severe convective rain cells formed at 10:10 on July 20 in northern Henan Province and maintained for 9.3 hours,continuously strengthened by the blocking effect of Taihang Mountains and Songshan Mountain and supplied by the water vapor in southeasterlies.The rainstorm began at the strongest stage of the convective rain cells.During the rainstorm,the size of the severe convective rain cells gradually decreased,and the cloud-top brightness temperature kept rising.The precipitation gradually weakened because the released instability energy and the dragging flow caused the rain cells to weaken.The research shows that the development and long-stay of severe convective Rain Cell,driven by continuous water vapor transport and topographic blocking,was the direct cause of the heavy rainstorm that struck Zhengzhou on July 20,2021.
Keywords："7.20"extreme rainstormtracking algorithmcloud-top brightness temperaturesevere convective cloud cluster
Publication Date：2024-06-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 517-525 )