行星波活动对不同类型SSW的影响  

Planetary Wave Activity and Its Impact on Different Types of SSW Events

作　　者：徐路扬[1] 陈权亮[1] 

机构地区：[1]成都信息工程大学大气科学学院/高原大气与环境四川省重点实验室,成都610225

出　　处：《高原气象》2016年第5期1389-1400,共12页Plateau Meteorology

基　　金：国家自然科学基金资助项目(41475037);四川省青年科技基金项目(2014JQ0019)

摘　　要：依据WMO（World Meteorological Organization）对平流层爆发性增温（SSW，stratospheric sudden warming）的定义．首先将1957—2002年期间的52次SSW事件分为31次强增温事件和21次弱增温事件，然后根据其极涡的形态将31次强增温事件分为20次极涡转移型事件和11次极涡分裂型事件。利用逐日的ECMWF的ERA-40再分析资料，对这20次极涡转移型、11次极涡分裂型强平流层爆发性增温（SSW）过程以及21次弱增温过程分别做了合成分析，研究了这三类爆发性增温期间平流层的变化以及平流层中下层行星波1波和2波的异常。结果表明：极涡转移型强SSW在增温盛期低温中心和极涡都会发生偏移，同时高纬风场反转，极涡分裂型强SSW则在增温盛期低温中心和极涡发生分裂，高纬风场反转，而弱SSW只有低温中心出现偏移，极涡和高纬风场均未出现明显异常；在爆发性增温前期，1波都会出现异常增幅，在波振幅到达最大值以后发生爆发性增温。当增温开始以后，极涡转移型和弱SSW的1波振幅在到达极值后，会维持6～8天，而极涡分裂型1波振幅增温开始后开始减小；极涡转移型和弱SSW期间2波也较为相似，在增温前期波动振幅也会出现一定程度的增幅，在增温后开始减小，而极涡分裂型会在增温后出现2波振幅的增幅。1波和2波EP通量的分析表明，极涡转移型和弱SSW期间1波EP通量会在前期和盛期有较强的上传，2波EP通量上传较弱，而极涡分裂型2波EP通量上传则较强。Based on the criteria of WMO （World Meteorological Organization）, 52 S SW （stratospheric sudden warming） events during＇1957- 2002 were firstly classified into two types： 31 major warming and 21 minor warming events, then 31 major warming events were divided into 20 vortex displacement events and 11 vortex splitting events according to their forms of vortex. Using the ERA-40 daily reanalysis data from ECMWF, com- position analysis was used to study these three types of SSW events from 1957 to 2002, including 20 vortex dis- placement major warming, l l vortex splitting major warming and 21 minor warming events. The changes of stratosphere of these three were studied, and the anomalies of lower stratospheric planetary wave-number l, wave-number 2 and the corresponding EP fluxes during the sudden warming period were also interviewed in de- tail. The results showed that the vortex displacement major warming offsets its low temperature center and the vortex, and reverses wind field of high latitude from westerly to easterly wind. The vortex splitting type splits its low temperature center and the vortex, and reverses wind field of high latitude into easterly wind as well as the vortex displacement event. Minor warming events only offsets its low temperature center, the vortex and wind field of high latitude remain stable. For all these three SSW types, the amplitude of wave-number 1 anomalously increases before the sudden warming and the amplitude of wave-number 1 reaches its climax when the warming occurs, but the climax reaching date and the degree of amplitude increase is different according to the different types. The vortex displacement events and minor warming events remain its climax of amplitude of wave-number 1 for approximately 6-8 days, while the vortex splitting type decreases its amplitude of wave number 1 when the warming occurs. As to the wave-number 2, the vortex displacement type and minor warming events are alike, the amplitudes increase before the sudden warming, and then decrease when th

关 键 词：平流层爆发性增温 行星波 EP通量 

分 类 号：P421.32[天文地球—大气科学及气象学]