豫北“7·9”特大暴雨的形成与极端性探析  

Analysis on Formation and Extremity of the 9 July Extreme Torrential Rain in the North of Henan Province

作　　者：司福意 张一平[1,3] 赵海青 李社宗[4] 王迪[1,3] Si Fuyi;Zhang Yiping;Zhao Haiqing;Li Shezong;Wang Di(Key Laboratory of Agrometeorological Support and Application Technique,CMA,Zhengzhou 450003,China;Jiaozuo Meteorological Office, Jiaozuo 454003,China;Henan Meteorological Observatory,Zhengzhou 450003,China;Zhengzhou Meteorological Office,Zhengzhou 450005,China)

机构地区：[1]中国气象局·河南省农业气象保障与应用技术重点开放实验室,郑州450003 [2]焦作市气象局,河南焦作454003 [3]河南省气象台,郑州450003 [4]郑州市气象局,郑州450005

出　　处：《气象与环境科学》2021年第1期65-73,共9页Meteorological and Environmental Sciences

基　　金：国家自然科学基金(41775044);河南省科技厅科技攻关项目(212102310025);中国气象局·河南省农业气象保障与应用技术重点开放实验室应用技术研究基金(KM202032、KZ201702、KM202002)。

摘　　要：2016年7月9日豫北发生了一场特大暴雨天气过程,新乡和辉县两个国家站日雨量超过400 mm,为河南仅逊于“75·8”特大暴雨日雨量的次高值,且其小时雨强与强降水持续时长均刷新了当地历史气象记录。利用常规观测资料、EC-ERA5(0.25°×0.25°)再分析资料、卫星和雷达等探测资料,对这次特大暴雨的形成机制进行了探讨。结果表明:华北冷涡是本次特大暴雨过程的主要天气影响系统。尽管天气系统偏弱,但极高的温湿环境场与适宜的高低空环流配置,有利于对流性暴雨的发生发展。远距离台风的登陆促成了一条伸向内陆的暖湿气流输送带,并在豫北太行山东麓迎风坡喇叭口处汇聚,形成超强的水汽辐合倾斜上升运动。强辐合上升运动维持时间长达6 h以上,导致了暴雨中心极端强降水的产生。系统的暴发机制归属于南方暖区暴雨的准正压类。卫星和雷达图像更直观地展现了特大暴雨形成的机理。“7·9”暴雨云系为尺度介于α与β之间的近圆形中尺度对流复合体(MCC),由多个较小尺度的强对流云团(MβCS)合并发展而成,中心回波体的发展有来自东北、西南、西北三个方向回波的汇聚,并呈现出后向传播的特性,表现出低质心结构的暖区暴雨特征。An extreme torrential rain event occurred in northern Henan on 9 July 2016,and the daily rainfall amount at Xinxiang and Huixian stations was more than 400 mm,being the second most daily rainfall in Henan only inferior to the event in August 1975.Moreover,both the hourly rainfall intensity and duration of the severe precipitation broke the local meteorological records.This paper investigates the formation mechanism and extremity of this extremely severe precipitation by using the MICAPS conventional observation,EC-ERA5(0.25°×0.25°)reanalysis data,satellite images and radar data.The results indicate that the North China cold vortex was the major impact system for this extreme torrential rain process.Although the weather system was weak,the extremely high temperature,high humidity and suitable high-low-altitude circulation configuration contributed heavily to the development of severe convective rainstorms.With the typhoon landing,a channel of warm moisture airflow was formed in the bottom of troposphere extending to the north of Henan province,and a continuous vapor convergence and slanting upward movement were generated near the trumpet mouth at the east foot of Taihang Mountain.The severe convergence upward movement lasted for more than 6 h,which resulted in the occurrence of extreme heavy precipitation in the rainstorm center.Its trigger mechanism was the quasi-barotropic type which belonged to the warm-sector rainstorm in South China.The satellite and radar images have provided a better picture of the mechanism by which the extreme torrential rain formed.The formation mechanism of the 9 July extreme rainstorm was intuitively showed by the evolutions of satellite and radar images,and its cloud system was a strong roughly circular mesoscale convective complex(MCC)from the merger of several small-scale mesoscale strong convective clouds(MβCS)with scales betweenαandβ.Obvious convergence of echoes from three directions of northeast,southwest and northwest contributed to the development of central echoes,and t

关 键 词：特大暴雨 华北冷涡 远距离台风 地形喇叭口 

分 类 号：P458.121.1[天文地球—大气科学及气象学]