气象科学2024，Vol.44Issue(3)：498-511,14.DOI:10.12306/2024jms.0005
东南风低空急流影响"21·7"郑州市极端暴雨分析
Analysis of the impact of southeast wind low altitude jet on the"21·7"extreme heavy rain in Zhengzhou City
摘要
Abstract
Based on the best path data of Tropical Cyclone(TC)from the Shanghai Typhoon Research Institute of the China Meteorological Administration,Final Analysis(FNL)data from the National Center of Environmental Prediction(NCEP)and the conventional observation data,the characteristic mechanism of the extreme heavy rain process in Zhengzhou in July 2021 was analyzed.Results show that:(1)two TCs simultaneously transport a large amount of water vapor over a long distance,and the relationship between the southeast low-level jet and heavy precipitation is closely related.When the southeast wind rushes northward to stations such as Taiyuan and Xingtai,the heavy rain in Zhengzhou City weakens.The variation of the number of stations with precipitation exceeding 62.5 mm in 6 hours in Zhengzhou City is consistent with the variation trend of geostrophic deviation values at 850 hPa.(2)Before the occurrence of extreme precipitation at Zhengzhou station on 20 July,the wind direction changed from southeast to southwest from 850 hPa to 500 hPa and then to 200 hPa.The Vertical Wind Shear(VWS)of horizontal winds at 200 hPa and 850 hPa decreases from its maximum value,the Precipitable Water Vapor(PWV)increases significantly,and the degree of instability decreases,which are favorable conditions for the occurrence of extreme heavy rain.Extreme rainstorm was produced by moisture convection.(3)The diagnosis of latitude and longitude wind variability indicates that the most favorable factor for maintaining 850 hPa easterly winds in Zhengzhou City is geostrophic deviation.The most favorable factor for increasing southerly winds is momentum advection.Momentum convection promotes a decrease of southerly wind at 850 hPa during the heavy rain process in Zhengzhou,so the transfer of momentum up and down is not the reason for the southerly wind increase at 850 hPa.关键词
极端暴雨/东南风低空急流/湿对流/地转偏差/南风动量平流Key words
extreme rainstorm/southeasterly low level jet/moisture convection/geostrophic deviation/south wind momentum advection分类
天文与地球科学引用本文复制引用
张端禹,崔春光,王晓芳,唐永兰,李山山..东南风低空急流影响"21·7"郑州市极端暴雨分析[J].气象科学,2024,44(3):498-511,14.基金项目
国家自然科学基金资助项目(42230612 （）
41975058 （）
42105012) （）
湖北省气象局科技发展基金重点项目(2022Z02) （2022Z02）
湖北省自然科学基金资助项目(2023AFD091) （2023AFD091）
中国气象局武汉暴雨研究所基本科研业务费专项(202402) （202402）
