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投稿时间:2024-05-09 修订日期:2024-10-23
投稿时间:2024-05-09 修订日期:2024-10-23
中文摘要: 登陆北上进入渤海的热带气旋多能引发辽东半岛强降水。利用《热带气旋年鉴》、云顶亮温和ERA Interim全球再分析资料,对北上过程中引发辽东半岛强降水的7个台风进行动态合成和诊断分析。结果表明:台风登陆北上过程中靠近中纬度高空槽,变性为半冷半暖结构,非对称结构明显;环境风垂直切变明显增大,台风垂直结构发生明显倾斜,其北侧中尺度对流活动发展旺盛,强降水主要分布在顺垂直切变方向的左侧。台风北上过程中与偏南风低空急流相连接,强度衰减缓慢,对流活动持续维持并有所加强。台风北上靠近槽前偏西风高空急流入口区,对流层高层辐散增强,有利于台风低压环流的维持及强降水的产生。槽后冷空气自台风西北侧对流层中高层倾斜下沉,向东南楔入低层,触发台风的东北侧、东南侧对流不稳定能量释放,深厚的上升运动发展。辽东半岛处于台风北侧强对流区,降水强度大、持续时间长。
中文关键词: 北上热带气旋,变性,强降水,辽东半岛
Abstract:The landfall tropical cyclones can often bring heavy precipitation to Liaodong Peninsula when they move northward into the Bohai Sea. Using CMA Tropical Cyclone Yearbook, cloud top brightness temperature and ERA-Interim reanalysis data, we conduct dynamic synthesis and diagnostic analysis of seven typhoons that caused heavy precipitation over the Liaodong Peninsula during their northward moving. The major conclusions are as follows. The typhoons experienced extratropical transition when approaching westerly troughs and had hybrid structures with remarkable baroclinic instability. Meanwhile, the vertical wind shear was enhanced, the vertical structure of the typhoon vortex slanted with height, and mesoscale convection developed on their north sides. The locations of heavy precipitation mainly occurred in the left side along with the direction of vertical wind shears. The standing link of typhoon with a deep southwestern or southeastern jet was favorable for the development of sustained convective activities in the typhoon rain belts, and the typhoons decayed slowly due to abundant moisture supply. Basically, strong-rainfall typhoons moved northward near the entrance area of the westerly jet stream in front of the trough, characterized by strong divergence in the upper layers. The coupling dynamical structure of positive divergence zone and the positive vorticity at lower levels formed, which was favorable for genesis of heavy precipitation and long-time substation of typhoon circulation. The cold air in the middle and upper troposphere invaded into typhoons’ northwest sides and the frontal zone slanted towards northwest with height, increasing the convective instability in the low-level front zone. The coupling dynamic structure of positive vorticity region and the divergence center further uplifted the air on their northeast sides and southeast sides. Liaodong Peninsula was in the north side of the typhoons, possessing strong low-level convergence, vertical wind shear, and deep and persistent vertical motion, thus the precipitation intensity was high and the duration was long over the Liaodong Peninsula.
keywords: northward-moving tropical cyclone, extratropical transition, heavy precipitation, Liaodong Peninsula
文章编号: 中图分类号:P447,P445 文献标志码:
基金项目:国家重点研发计划(2023YFC3008501)、环渤海区域科技协同创新基金项目(QYXM202108、QYXM202208、QYXM202402、QYXM202403)和中国气象科学研究院灾害天气国家重点实验室开放课题(2024LASW-B14)共同资助
作者 | 单位 |
梁军 | 大连市气象台,大连 116001 |
张胜军 | 中国气象科学研究院灾害天气国家重点实验室,北京 100081 |
贾旭轩 | 大连市气象台,大连 116001;中国气象科学研究院灾害天气国家重点实验室,北京 100081 |
冯呈呈 | 大连市气象台,大连 116001 |
李婷婷 | 大连市气象台,大连 116001 |
李思绪 | 大连市气象台,大连 116001 |
引用文本:
梁军,张胜军,贾旭轩,冯呈呈,李婷婷,李思绪,2024.登陆北上台风结构变化及其引发的辽东半岛强降水分析[J].气象,50(11):1306-1316.
LIANG Jun,ZHANG Shengjun,JIA Xuxuan,FENG Chengcheng,LI Tingting,LI Sixu,2024.Analysis on Structure Changes of Landfall Northbound Typhoons and the Heavy Precipitation in Liaodong Peninsula Induced by Them[J].Meteor Mon,50(11):1306-1316.
梁军,张胜军,贾旭轩,冯呈呈,李婷婷,李思绪,2024.登陆北上台风结构变化及其引发的辽东半岛强降水分析[J].气象,50(11):1306-1316.
LIANG Jun,ZHANG Shengjun,JIA Xuxuan,FENG Chengcheng,LI Tingting,LI Sixu,2024.Analysis on Structure Changes of Landfall Northbound Typhoons and the Heavy Precipitation in Liaodong Peninsula Induced by Them[J].Meteor Mon,50(11):1306-1316.