四川盆地一次西南低涡影响下的飑线天气特征及其成因

扫码查看

原文链接

万方数据
维普

中文摘要：2019年6月4日夜间到5日白天，四川盆地东部出现一次西南低涡影响下的飑线过程，采用多源观测及欧洲中心再分析资料，分析此次飑线过程的特征及成因。结果表明:飑线形成前四川盆地中部已出现暴雨，该对流性暴雨在高空低槽和暖性西南低涡的环流背景下产生，相应的对流层大气湿层深厚且具有一定对流有效位能。飑线发生在冷空气翻越秦岭进入西南低涡后部的显著锋生过程中，在高空低槽、西南低涡及强冷锋的共同影响下，冷锋垂直环流与西南低涡垂直环流合并，锋区抬升机制显著增强，为飑线在重庆西部形成提供了有利的动力抬升条件。重庆西部的大气环境有利于飑线形成，具有较大的对流层中下层垂直减温率、对流有效位能及深层垂直风切变，且对流层中层干空气特征显著。雷达上表现为冷切变线形成的线状对流与西南低涡锋生区中的强降雨对流合并发展，在重庆西部形成"人字形"回波，回波后部边界层内由前期暴雨形成的冷区在冷锋南下和锋后干空气中的雨滴蒸发冷却作用下进一步降温形成冷池出流，利于飑线的形成;弓状飑线在形成之后维持了约1。5 h。冷锋后部强低空水平动能的向南及向下输送，以及地面冷暖空气间位温梯度的显著增强，均有利于地面大风的形成。

外文标题：Characteristic and Formation of a Squall Line Influenced by the Southwest Vortex in Sichuan Basin

外文摘要：One squall line influenced by the southwest vortex occurred in the eastern part of Sichuan Basin from the night of 4 June to the day of 5 June 2019.Using multi-source observation data and ECMWF Re-analysis data,the characteristics and formation of the squall line are analyzed.The results show that con-vective heavy rainfall before the occurrence of the squall line was formed in the central Sichuan Basin under the background of the high-altitude trough and the warm southwest vortex,combined with troposphere atmospheric environment of the deep wet layer and certain convective available potential energy(CAPE).The squall line occurred during the prominent frontogenesis process of cold front which surmounted the Qinling Mountains and entered the rear of the southwest vortex.With the joint influence of the high-altitude trough,southwest vortex and strong cold front,the cold front vertical circulation merged with the southwest vortex vertical circulation,and the combined vertical circulation circle significantly strengthened the uplift mechanism of the frontal zone,which provided favorable dynamic lifting conditions for the for-mation of the squall line in western Chongqing.The atmospheric environment in western Chongqing was conducive to the formation of the squall line.There was dry air in the middle troposphere,large vertical temperature lapse rate in the lower and middle troposphere layers,significant CAPE,and large deep verti-cal wind shear.The formation process of the squall line observed by radar was characterized by the com-bined development of linear convection with the cold shear line and strong rainfall convection in the south-west vortex frontogenesis region,forming the"herringbone"echo in the west of Chongqing.The cold front behind the"herringbone"echo moved southward,and combined with the evaporation and cooling of raindrops in the dry environment behind the front,cooled down the cold area formed by the rainstorm to the cold pool outflow in the boundary layer,promoting the formation of the squall line.The arc-shaped squall line maintained for about 1.5 h after its formation.The southward and downward transport of low-level horizontal kinetic energy at the rear of the front area and the enhancing of the potential temperature gradient between the surface cold and warm air during the formation of the squall line all contributed to the formation of the surface gales.

外文关键词：

severe convectionsquall linebow echosouthwest vortexcold front

作者：

邓承之、周国兵、李强、刘伯骏、夏蘩

展开 >

作者单位：

中国气象局气候资源经济转化重点开放实验室,重庆 401147

重庆市气象台,重庆 401147

重庆市气象局,重庆 401147

关键词：

强对流飑线弓形回波西南低涡冷锋

基金：

国家自然科学基金气象联合基金重点项目中国气象局创新发展专项重庆市自然科学基金面上项目重庆市自然科学基金面上项目重庆市自然科学基金面上项目中国气象局西南区域气象中心创新团队基金重庆市气象部门业务技术攻关项目

项目编号：

U2242202CXFZ2022J011CSTB2022NSCQ-MSX0665CSTC2021JCYJ-MSXMX0057CSTB2022NSCQ-MSX1461XNQYCXTD-202202YWJSGG-202201

出版年：

2024

DOI：

10.7519/j.issn.1000-0526.2024.043001

气象

国家气象中心

气象

CSTPCD北大核心

影响因子：2.337

ISSN：1000-0526

年,卷(期)：2024.50(7)