摘要
利用NCEP/NCAR逐日再分析资料、国家气象站降水资料及高分辨率地形资料,分析河南2021年7月1722日极端暴雨过程的时空分布特征,重点研究对其影响显著的平流层高位涡侵入特征、影响过程和形成机理,以及对流层中低层环流对这次暴雨过程的协同影响。结果表明:(1)此次暴雨过程持续时间长、影响范围广,造成太行山东麓沿山地区及伏牛山东侧的郑州、焦作和鹤壁等多地累积降水量突破400.0 mm。(2)在暴雨发展和峰值阶段,河南以西上空出现的平流层高位涡侵入,在河南上空对流层高层(低层)激发出异常强烈的辐散(辐合),促进上升运动强烈发展,这是暴雨形成的重要原因。(3)南亚高压东缘的南北走向及向青藏高原的西退,使青藏高原东部高层北风异常偏强,有助于引导中纬度高位涡空气向南、向下输送,为河南以西上空平流层高位涡侵入的形成提供了有利的大尺度环流背景。(4)与日本上空强烈的高压异常中心相对应,西太平洋副热带高压位置偏北、强度偏强且稳定少动,在其西南侧有台风“烟花”活动,二者之间异常强盛的偏东气流将洋面上的暖湿空气源源不断地输送到河南,为暴雨的发生提供了有利的水汽条件。
By using NCEP/NCAR daily reanalysis data,observational rainfall data of national meteorological stations and high-resolution topographic data,this paper analyzes the spatial and temporal distribution of the extremely severe torrential rain event during 1722 July,2021 in Henan Province,and investigates the characteristics and formation mechanisms of stratospheric high potential vorticity(PV)intrusion and its effects on the extremely severe torrential rain.Besides,the collaborative influence of circulations in the middle and lower troposphere are also analyzed.The findings are as follows:(1)This extreme rainstorm event lasted for a long time and had a wide range of impact areas.The accumulated precipitation in the areas along the eastern foot of Taihang Mountains and in Zhengzhou,Jiaozuo,Hebi,etc.located to the eastern slope of Funiu Mountain to exceed 400.0 mm.(2)During the developing and peak phases of the severe rainstorm,stratospheric high PV intrusion occurred to the west of Henan,exciting anomalously strong divergence(convergence)in the upper(lower)troposphere over Henan,thus contributing to vigorous development of upward motion,which was critical to the formation of the extremely severe torrential rain.(3)The south-north east edge of South Asian high(SAH)retreated westward towards the Tibetan Plateau(TP),resulting in anomalously strong northerlies in the upper troposphere over the eastern TP,which favored the southward and downward transport of mid-latitude high PV air,providing favorable large-scale circulation background for the formation of stratospheric high PV intrusion over the areas west of Henan.(4)Corresponding to a high anomaly center over Japan,the western Pacific subtropical high stayed stable by north with stronger intensity,accompanied by activity of Typhoon“IN-FA”in its west side.Anomalously strong easterlies between them transported the warm and moist airs from the western Pacific to Henan continuously,providing the extremely severe torrential rain with abundant water vapor.
作者
祝传栋
陈正洪
李亚飞
许杨
张冠舜
廖洁
Zhu Chuandong;Chen Zhenghong;Li Yafei;Xu Yang;Zhang Guanshun;Liao Jie(Hubei Meteorological Service Center,Wuhan 430205,China;State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;Tianjin Meteorological Disaster Defense Technology Center,Tianjin 300074,China;Guangzhou Institute of Tropical and Marine Meteorology,China Meteorological Administration,Guangzhou 510641,China)
出处
《气象与环境科学》
2022年第2期27-37,共11页
Meteorological and Environmental Sciences
基金
国家自然科学基金项目(42105039)。
关键词
极端暴雨
平流层高位涡侵入
南亚高压
对流层中低层环流
extremely severe torrential rain
stratospheric high potential vorticity intrusion
South Asian high
circulation in the middle and lower troposphere
