“21·7”河南特大暴雨水汽和急流特征诊断分析  

Diagnostic Analysis on Water Vapor and Jet Characteristics of the July 2021 Severe Torrential Rain in Henan Province

作　　者：汪小康[1] 崔春光[1] 王婧羽 杨浩[1] 周文 WANG Xiaokang;CUI Chunguang;WANG Jingyu;YANG Hao;ZHOU Wen(Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,CMA,Wuhan 430205)

机构地区：[1]中国气象局武汉暴雨研究所暴雨监测预警湖北省重点实验室,武汉430205

出　　处：《气象》2022年第5期533-544,共12页Meteorological Monthly

基　　金：国家自然科学基金国际合作项目(41620104009);国家自然科学基金青年项目(41705019);湖北省气象局科技课题重点项目(2020Z05);湖北省气象局科技发展基金(2020Y04);气象灾害教育部重点实验室&气象灾害预报预警与评估协同创新中心联合开放课题(KLME202106)共同资助。

摘　　要：2021年7月中下旬在河南省发生了一场极端强降水过程,暴雨持续时间长,累计降水量大,落区集中,造成了严重的人员伤亡。基于自动站雨量数据和ERA5再分析数据探讨了多尺度系统、急流和地形对水汽的输送和辐合及降水形成的重要作用和影响机制。结果发现:暴雨发生在远距离台风影响的有利环流背景之下,大量来自西太平洋的水汽从边界层和对流层低层进入河南东侧,来自南海的水汽从南侧对流层中低层进入降水区,在低涡、切变线和辐合线的共同作用下,引发强降水。低空急流与边界层急流的耦合形成低层水汽辐合上升中心,地形起到了动力阻挡抬升和热力抬升作用,并与急流综合作用,使强降水呈带状出现在山前,且20日位于豫中,21日在豫北。In mid-late July 2021,an extreme heavy rainfall process with the characteristics of long duration,large accumulated rainfall amount,and concentrated precipitation area occurred in Henan Province,causing serious casualties.Based on automatic station rainfall data and ERA5 reanalysis data,the important functions and influence mechanisms of multiscale system,jet and topography on the transport and convergence of water vapor and the formation of precipitation are discussed in this paper.It is found that the severe torrential rain occurred in the favorable circulation conditions with long-distance typhoon(In-fa).A large amount of water vapor coming from the western Pacific penetrated the east border of Henan Province from lower layer,while the water vapor from the South China Sea entered Henan Province from the south side mainly in the middle-low layers of troposphere,resulting in the extreme heavy rainfall under the joint influence of cyclonic vortex,shear line and convergence line.The centers of water vapor convergence and ascending motion in lower layers were caused by the coupling impact of low-level jet and boundary layer jet.In addition,the terrain here played the roles of dinamically blooking and lifting,and thermodynamically lifting at the same time.Besides,combined with the jet,topography made the severe precipitation present as a band shape in front of the mountain,and located in the central part on the 20th July and in the northern part of Henan Province on 21 July 2021.

关 键 词：河南特大暴雨 水汽输送和辐合 低空急流耦合 地形作用 

分 类 号：P458[天文地球—大气科学及气象学]