“21·7”河南持续性暴雨成因分析  

Analysis on the Cause of“21·7”Persistent Heavy Rainfall in Henan

作　　者：刘静[1] 靳莉君[1] 韩作强 张利娜[1] LIU Jing;JIN Lijun;HAN Zuoqiang;ZHANG Lina(Bureau of Hydrology,Yellow River Conservancy Commission,Zhengzhou 450004,China)

机构地区：[1]黄河水利委员会水文局,河南郑州450004

出　　处：《水文》2023年第5期69-75,共7页Journal of China Hydrology

基　　金：国家自然科学基金面上项目(42171024)。

摘　　要：采用水文站、气象站逐日降水数据和ERA5再分析资料,详细分析了2021年7月18—22日发生在河南中北部的持续性暴雨过程的大气环流背景、水汽输送特征以及动力热力结构,结果表明:(1)南亚高压东北延伸、高空急流增强、大陆高压和西太副高稳定对峙、黄淮低涡缓慢西移、西北太平洋和南海双台风互旋持续输送水汽,为暴雨发生和持续提供了有利的背景条件,太行山和嵩山等山脉对暴雨具有增幅作用;(2)暴雨区水汽主要来源于对流层低层偏东风气流对西北太平洋暖湿空气的持续输送,水汽辐合层的深厚程度以及辐合强弱对暴雨强度预报具有一定的指示意义;(3)暴雨区上空强散度柱以及强上升运动是20日和21日极端暴雨发生的重要动力机制,高温高湿大气层结的发展为大暴雨的形成提供了有利的对流不稳定条件。Based on the daily precipitation data of hydrological stations and meteorological stations and ERA5 reanalysis data,the atmospheric circulation background,water vapor transport characteristics and dynamic and thermodynamic structure of the continuous rainstorm process that occurred in central and northern Henan during July 18-22 in 2021 were analyzed in detail.The results show that,(1)The northeast extension of the South Asian High,the strengthening of the upper-air jet stream,the stable confrontation between the continental high and the West Pacific Subtropical High,the slow westward movement of the Huang-Huai vortex,and the continuous water vapor transport by twin typhoons respectively located in the northwest Pacific and the South China Sea uni‐formly provided favorable background conditions for the occurrence and persistence of heavy rain.Besides,mountains such as Tai‐hang Mountain and Songshan Mountain intensified the rainstorm.(2)The water vapor was mainly from the northwest Pacific Ocean continuously transported by the easterly air in the lower troposphere.The depth and strength of moisture convergence showed certain indication significance for rainstorm intensity forecast.(3)The intensive divergence column and the strong upward movement were the important dynamic mechanism for the extreme rainstorm on July 20 and July 21.Simultaneously,atmospheric stratification with high temperature and high humidity provided favorable convective instability conditions for the heavy rainfall.

关 键 词：持续性强降水 环流背景 水汽输送 物理量诊断 

分 类 号：P333[天文地球—水文科学]