1710号台风“海棠”外围龙卷大气环境条件和雷达特征分析  

Synoptic Situation and Radar Characteristics of Tornado in Outside-Region of Typhoon Haitang

作　　者：汤洁[1] 徐芬[2,3] 吴海英[2,4] 夏网萍[1] 安礼政 TANG Jie;XU Fen;WU Haiying;XIA Wangping;AN Lizheng(Huaian Meteorological Observatory,Jiangsu,Huaian 223001;Key Laboratory of Transportation of Meteorology,CMA,Nanjing 210008;Jiangsu Institute of Meteorological Sciences,Nanjing 210009;Jiangsu Meteorological Observatory,Nanjing 210008)

机构地区：[1]江苏省淮安市气象局,淮安223001 [2]中国气象局交通气象重点开放实验室,南京210008 [3]江苏省气象科学研究所,南京210009 [4]江苏省气象台,南京210008

出　　处：《气象科技》2021年第2期235-243,共9页Meteorological Science and Technology

基　　金：国家重点研发计划资助项目(2018YFC1506103);中国铁路总公司重大课题(K2018T007);江苏省科技厅项目(BE2017776);江苏省预报员专项(JSYB202013);淮安市气象科研项目(201901)共同资助。

摘　　要：2017年8月1日18:10—18:30受1710号台风"海棠"外围螺旋雨带影响,江苏省淮安市淮安区出现EF1级龙卷。利用常规观测资料、NCEP 1°×1°再分析资料、多普勒雷达资料等,对龙卷过程进行分析。结果显示:龙卷发生在"海棠"残留低压和副高边缘间的东南暖湿急流中,其发生前1h地面出现小尺度涡旋并沿着地面辐合线移动。龙卷影响时,相邻地面自动站观测到气压上升、气温和露点下降、风力明显增大。逐渐增大的对流有效位能、小的对流抑制能量、较大的0~1km垂直风切变、1km以下的抬升凝结高度、干侵入等环境场特征均有利于本次龙卷风暴的生成。淮安多普勒雷达探测到入流缺口、TVS特征、气旋性风场结构。通过垂直螺旋度分析和双多普勒雷达风场反演等方法,发现在龙卷发生前低层环境垂直风切变有利于小尺度涡旋生成,中低层水平风场以辐合为主。当出现龙卷时,气旋式辐合中心下降有利于涡旋触地,龙卷发生地位于低层涡旋移动方向左前侧与1km高度切变线附近。In the outer rain band of Typhoon Haitang,an EF1 tornado struck the Huaian District of Huaian,Jiangsu Province from 18:10 to 18:30 on 1 August 2017.Using the data of conventional observation,NCEP 1°×1°reanalysis data,and Doppler weather radar observation,this paper analyzes a tornado process.The results show that the tornado occurred in the southeast warm and wet jet between the residual low pressure of the typhoon and the edge of the subtropical high.One hour before the occurrence,the small-scale vortex appeared on the ground and moved along the ground convergence line.The adjacent ground automatic station observed an increase in air pressure,a decrease in temperature and dew point,and a significant increase in wind force when the tornado passed by.Increasing convective available potential energy,small convection inhibition energy,large vertical wind shear between 0 and 1 km,low lifting condensation level,and dry intrusion were all conducive to the formation of this tornado storm.Huaian Doppler radar detected the inflow gap,TVS characteristic,and cyclonic wind field structure.Based on the vertical helicity analysis and double Doppler radar wind field inversion methods,the structures and evolutions of tornado are studied.It is found that the small-scale vortices had generated in the vertical wind shear of the lower environment before the tornado occurred.The horizontal wind field was dominated by convergence.When the tornado occurred,the descending of cyclonic convergence center was favorable for the vortex to touch the ground.The tornado appeared on the left front of the vortex in the lower level and formed in the horizontal wind shear below 1.5 km.

关 键 词：台风龙卷 天气背景 雷达回波特征 风场反演 

分 类 号：P445[天文地球—大气科学及气象学]