秋台风“梅花”造成浙江极端降水成因分析  

Analysis of extreme precipitation in Zhejiang Province caused by Typhoon"Muifa"

作　　者：钱卓蕾 沈哲文 左骏 QIAN Zhuolei;SHEN Zhewen;ZUO Jun(Shaoxing Meteorological Office,Shaoxing 312000,China;Shaoxing Meteorological Disaster Prevention and Mitigation Center,Shaoxing 312000,China)

机构地区：[1]绍兴市气象台,浙江绍兴312000 [2]绍兴市气象防灾减灾中心,浙江绍兴312000

出　　处：《海洋预报》2024年第2期104-116,共13页Marine Forecasts

基　　金：浙江省气象局重点项目(2021ZD28);浙江省气象局预报员专项(2021YBY10)。

摘　　要：利用全球降水观测计划卫星降水率产品、地面加密自动站和ERA5再分析资料,对202212号台风“梅花”造成浙江极端降水的成因进行分析。结果表明:台风“梅花”造成的极端降水主要分布在沿海和四明山区,极值在四明山区,9月12—13日强降水由台风北侧外围雨带造成,14日则主要为台风本体降水;高层西南风急流的稳定以及台风“梅花”在移动过程中与西风槽结合有利于维持台风强度并引起台风动力结构不对称;台风“梅花”与副热带高压间的东风是台风发展的主要水汽来源,西太平洋上热带气旋的存在也有利于台风“梅花”北侧水汽输送加强,导致台风强降雨带偏北;台风“梅花”北侧高层始终有位涡下传至对流层中低层,促使低层扰动中心的发展,冷空气侵入造成浙江东部中尺度斜压锋生;受四明山地形影响,台风“梅花”环流西北侧的偏北风进入内陆后形成中尺度辐合线,山前抬升,山后下沉,有利于山前降水增幅。By using GPM satellite 3-IMERGM precipitation rate product,ground encryption automatic station and ERA5 reanalysis data,the causes of extreme precipitation in Zhejiang Province during Typhoon“Muifa”(202212)are analyzed.The results show that the extreme precipitation mainly locates in the coastal area and Siming Mountain area with extreme value in the Siming Mountain area.The heavy precipitation is caused by the north outer rain belt of the typhoon on September 12-13,but due to the typhoon body on September 14.The stability of the high-level southwesterly jet and the typhoon's combination with the westerly trough during its moving benefit for the maintain of the typhoon intensity and leads to the asymmetry of the typhoon dynamic structure.The easterly jet between the typhoon and the subtropical high is the main water vapor source for the typhoon's development.The existence of another tropical cyclone over the western Pacific is also conducive to strengthen the water vapor transport on the northern side of the typhoon,which leads to the heavy north rain belt of the typhoon.There are always potential vortex disturbances in the upper layer of the north side of the typhoon flowing down to the middle and lower troposphere,which promotes the development of disturbance center in the lower troposphere.Meanwhile,cold air invades and causes mesoscale baroclinic frontogenesis in eastern Zhejiang Province.Affected by the topography of Siming Mountain,the northerly winds on the northwest side of the typhoon enter the inland and form a mesoscale convergence line.The air flow rises in front of the mountain and sinks in the back of the mountain,which is conducive to the increase of precipitation.

关 键 词：极端降水 外围雨带 等熵位涡 锋生 地形 

分 类 号：P444[天文地球—大气科学及气象学]