西北太平洋台风群发事件年代际变化特征分析  

Characteristics of the interdecadal variation of multiple tropical cyclone events in the western North Pacific

作　　者：张可 方娟[1,2] ZHANG Ke;FANG Juan(School of Atmospheric Sciences,Nanjing University,Nanjing 210023,China;Key Laboratory of Mesoscale Severe Weather(Nanjing University),Ministry of Education,Nanjing 210023,China)

机构地区：[1]南京大学大气科学学院,南京210023 [2]中尺度灾害性天气教育部重点实验室,南京210023

出　　处：《气象科学》2021年第5期584-596,共13页Journal of the Meteorological Sciences

基　　金：国家重点研发计划项目(2018YFC1505901);国家自然科学基金资助项目(41875067)。

摘　　要：利用台风最佳路径资料和全球再分析数据集分析了1979—2018年6—10月西北太平洋地区台风群发事件的统计特征。期间所有台风个例根据群发性质被分为三类:第一类为单独生成的非群发台风;第二类为群发事件中生成,但事件中仅有2个台风成员的“MTC2”台风;第三类为群发事件中生成,且事件中有3个或3个以上台风成员的“MTC3”台风。结果表明,相对于MTC2台风,MTC3台风生成时位置偏北,环境场季风槽辐合更强、高温海区范围更大、中低层大气更湿润。而MTC3台风在1990s末的突变减少导致了西太台风群发事件和台风总数减少。1996年之后,尽管洋面上空仍有较多的热带涡旋扰动,但群发台风活跃的大部分地区垂直风切变增强、高空辐散和季风槽辐合减弱以及西太平洋热带季节内振荡事件(Madden-Julian Oscillation,MJO)的对流活跃位相维持日数减少,它们共同导致了MTC3事件的年代际变化。By using best-track data and global reanalysis dataset,the statistical characteristics of Multiple Tropical Cyclone(MTC)events in the western North Pacific(WNP)from June to October during 1979-2018 were analyzed.According to the different number of MTC members,all Tropical Cyclone(TC)generated during the period were divided into three categories:(1)single typhoon which generated individually;(2)‘MTC2’typhoon generated in MTC events,but with only two typhoon members;(3)‘MTC3’typhoon generated in MTC events with three or more typhoon members.Results show that compared with MTC2 typhoon,MTC3 typhoon can generate in the northern region and has stronger monsoon trough convergence,larger range of high-temperature sea area and more humid mid-bottom atmosphere.In addition,the sudden decreasing of MTC3 typhoon in the late 1990s led to a decreasing in the numbers of MTC events and typhoons in the WNP.After 1996,there are still more tropical disturbances over the ocean surface,however,in most areas with active mass typhoons,it can be seen that the combination of increasing of vertical wind shear,the decreasing of upper-level divergence,the weakness of monsoon trough convergence and the decreasing of the lasting days of Madden-Julian Oscillation(MJO)convective phase in WNP led to the interdecadal change of the MTC3 event.

关 键 词：台风群发 热带涡旋扰动 垂直风切变 MJO 年代际变化 

分 类 号：P732[天文地球—海洋科学]