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投稿时间:2016-05-09 修订日期:2017-05-26
投稿时间:2016-05-09 修订日期:2017-05-26
中文摘要: 本文应用多种常规观测资料和非常规观测资料,以两个强度差异较大的台风(201409号台风威马逊和200606号台风派比安)在内陆造成的台前飑线为研究对象,从飑线产生的实况、大尺度环流背景及飑线不同阶段进行分析,重点以飑线初生阶段的环境条件和成熟阶段的地面中尺度特征、垂直结构进行对比分析。分析结果表明:(1)“威马逊”飑线主要是台风倒槽和副热带高压(以下简称“副高”)的相互作用引起的;而“派比安”飑线则是由台风倒槽、副高、西风槽相互作用引起的;两次过程副高位置的不同造成台风外围东南急流位置的差异,“派比安”飑线过程中东南急流更有利于飑线的持续。(2)飑线初生阶段,充沛的水汽来源、明显的条件不稳定、不稳定能量的积累、对流抑制能量的减小均为飑线的初生提供了有利的条件,地面辐合线使得离散的对流单体组织发展成飑线;而水汽条件、地面辐合线位置的差异导致了两次飑线初生位置的不同; 对流有效位能(CAPE)、对流抑制位能(CIN)差异预示着“派比安”飑线过程对流发展潜势强于“威马逊”飑线过程。(3)飑线成熟阶段:由地面温压场特征分析出“派比安”飑线冷池中心比“威马逊”飑线更明显;垂直动力结构更有利于强对流的产生和发展。(4)西风槽底部和台风倒槽顶部在湘北的结合,使得已衰减的“派比安”飑线再次增强发展形成Ⅱ阶段飑线。(5)和以往研究的西风带飑线相比,这两次飑线过程并没有分析出那么强的“雷暴高压”、正变压,但有冷池、明显的温度梯度、气压梯度,低层的垂直风切变主要是由风的方向变化所导致。
Abstract:Based on conventional and unconventional observation data, and with squall lines preceding tropical cyclone caused by two typhoons (Typhoon 201409 Rammasun and Typhoon 200606 Prapiroon) of great intensity differences in inland (Hunan Province and Jiangxi Province) as analysis objects, we diagnosed reasons of differences from the aspects of observation, large scale circulation background and difference stages of squall line. Our contrastive analysis focused on environmental circumstances of initial stage, surface mesoscale characteristics and vertical structure of mature stage. The results show that inverted typhoon trough and subtropical high lead to the squall line preceding Rammasun, while squall line preceding Prapiroon is caused by the inverted typhoon trough, subtropical high and westerly trough; the different locations of subtropical high bring about the difference between positions of southeast jet surrounding these two typhoons, and the southeast jet surrounding Prapiroon is more favorable to the maintenance of squall line. In the initial stage, abundant vapor source, distinct convective instability, accumulation of instable energy and decrease of convective inhibition provide beneficial conditions, and the scattered convective cells are organized into squall lines by the surface convergence line; the different vapor conditions and locations of surface convergence line lead to different positions of two squall lines initially; potential instability of conditional unstable air layer, CAPE (convective available potential energy) and CIN (convective inhibition) indicate the convective development potential of squall line Prapiroon is more intense than the squall line Rammasun. The temperature characteristics of squall line preceding Prapiroon is more evident than that of Rammasun; vertical dynamic structure benefits the generation and development of severe convection; compared with previous research on westerly squall lines, thunderstorm high and positive variation of pressure are not found in these two squall line processes, but cold pool, distinct temperature gradient and pressure gradient have been detected, and vertical wind shear in the bottom layer relies mainly on the wind vector difference. When the bottom of westerly trough and the top of inverted typhoon trough are combined in the north of Hunan Province, convective cells strengthen and form the squall line of later stage. Compared with previous westerly squall line, during the two squall line processes, strong thunderstorm high pressure and positive pressure are not fingered out instead of cold pool, obvious temperature gradient and pressure gradient, and the lower vertical wind shear is given by the wind vector difference.
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基金项目:中国气象局预报预测核心业务发展专项(CMAHX20160210)、中国气象局灾害天气国家重点实验室开放课题重点项目(2014LASW A03)和国家自然科学基金项目(41475041)共同资助
引用文本:
唐明晖,姚秀萍,王强,丁小剑,2017.不同强度台风相伴随的内陆台前飑线对比分析[J].气象,43(8):912-923.
TANG Minghui,YAO Xiuping,WANG Qiang,DING Xiaojian,2017.Contrastive Analysis of Inland Pre TC Squall Line Accompanied by Typhoons with Different Intensities[J].Meteor Mon,43(8):912-923.
唐明晖,姚秀萍,王强,丁小剑,2017.不同强度台风相伴随的内陆台前飑线对比分析[J].气象,43(8):912-923.
TANG Minghui,YAO Xiuping,WANG Qiang,DING Xiaojian,2017.Contrastive Analysis of Inland Pre TC Squall Line Accompanied by Typhoons with Different Intensities[J].Meteor Mon,43(8):912-923.