华北冷涡背景下强对流天气的基本特征分析  

THE BASIC FEATURES OF THE SEVERE CONVECTION AT THE BACKGROUND OF COLD VORTEX OVER NORTH CHINA

作　　者：郁珍艳[1] 何立富 范广洲[3] 李泽椿 苏永玲[4] 

机构地区：[1]浙江省气候中心,浙江杭州310017 [2]国家气象中心,北京100081 [3]成都信息工程学院/高原大气与环境研究中心,四川成都610225 [4]青海省气象局,青海西宁810100

出　　处：《热带气象学报》2011年第1期89-94,共6页Journal of Tropical Meteorology

基　　金：科技部公益性行业专项(GYHY200706042)资助

摘　　要：利用京津冀的危险天气报资料,统计分析2001—2008年5—8月华北冷涡背景下的强对流天气的时空分布及动力热力特征。结果表明:(1)短时强降水在沿海地区发生的概率最大,尤其是下午至傍晚。河北西北山区上午发生大风和冰雹的概率最大,下午至傍晚的大概率区向东向南明显扩大。龙卷在上午发生的概率最大,其大概率中心位于北京。(2)对流大风以西北风为主,风力多为8级。冰雹直径以5～20 mm为主。短时强降水的持续时间多在20分钟以内,降水量多为20～23 mm。对流强度的大值区位于太行山、燕山的背风坡和沿海地区。(3)在短时强降水发生前的最有利抬升指数(BLI)最大、抬升凝结高度(LCL)最高。(4)大风发生前的垂直风切变最强,抬升凝结高度最低。(5)冰雹发生前0℃高度约为3 400 m,-20℃高度约为6 400 m,风暴的相对螺旋度(SRH)>150 m2/s2。The risk weather data in Beijing,Tianjin and Hebei are used to analyze the temporal-spatial distribution as well as the dynamic-thermal characteristics of the severe convection associated with cold vortex over North China during 2001—2008 from May to August.The results indicate that：（1） Short-term heavy precipitation had the largest occurrence probability in coastal areas,especially during the afternoon to evening.The strong wind and hail had the largest probability during morning in the mountain of Northwest Hebei,and the region of large probability expanded southward and eastward from the afternoon to evening.The largest occurrence probability of tornado was in the morning,the center was in Beijing.（2） There were northwest wind mostly,and gale mainly;most hail diameter were 5～20 mm;short-term heavy precipitation occurred mainly lasting less than 20 minutes,and the precipitation were 20～23 mm mostly.The large convection intensity was located in the leeward of Taihang and Yanshan Mountains and the coastal areas.（3） Before the occurrence of short-term heavy precipitation,the vapor was the most favorable,the Convective Available Potential Energy（CAPE） and Best Lifting Index（BLI） were the largest,but the Lifting Condensation Level（LCL） was the highest.（4） Before the occurrence of strong wind,the vertical wind shear was the strongest,the LCL was the lowest.（5） Before the occurrence of hail,the height of 0 ℃ was about 3 400 m,the height of-20 ℃ was about 6 400 m,the Storm Relative Helicity（SRH）150 m2/s2.

关 键 词：天气学 统计特征 强对流 华北冷涡 对流参数 

分 类 号：P424[天文地球—大气科学及气象学]