热带西太平洋季内震荡相关的赤道开尔文波对厄尔尼诺事件影响的初步探索  

Influence of MJO-related equatorial Kelvin waves on El Nino events in the western tropical Pacific

作　　者：于毅 孟祥凤[2] 周艺 孙树壮 YU Yi;MENG Xiangfeng;ZHOU Yi;SUN Shuzhuang(Weihai Meteorological Bureau,Weihai 264200,China;Ocean University of China,Qingdao 266100,China)

机构地区：[1]威海市气象局,山东威海264200 [2]中国海洋大学,山东青岛266100

出　　处：《海洋气象学报》2018年第3期92-100,共9页Journal of Marine Meteorology

基　　金：中国科学院战略先导科技专项(XDA11010204)

摘　　要：从海洋Kelvin波的角度研究了热带西太平洋季节内振荡(Madden-Julian Oscillation,MJO)对厄尔尼诺(El Nino)事件的影响。通过资料处理确定了热带西太平洋MJO相关的风应力强迫产生的海洋Kelvin波指数K,该指数代表了Kelvin波的强度。通过对比指数K与温跃层深度的变化,分析指出当El Nino事件发展过程中出现强MJO相关的海洋Kelvin波,并且该东传波动传递的是温跃层异常下沉信号时,会增大El Nino事件的振幅,对El Nino事件的发展起到重要的促进作用(1997/1998年El Nino事件);当MJO相关的海洋Kelvin波较弱时对El Nino事件影响不大,而且当传递的是温跃层异常上升信号时反而会对El Nino事件的发生与发展起到阻碍作用。总之,热带西太平洋MJO事件对El Nino事件在特定的情况下有重要影响,但并不能决定El Nino事件的发生或终结。The influence of MJO on El Nino events in the western tropical Pacific is explored from the perspective of Kelvin waves. A Kelvin waves index （ K ） by wind stress associated with MJO is derived from surface wind data. The index represents the intensity of Kelvin waves. By comparing the changes of the index K and the depth of main thermocline, it is denoted that when strong MJO-related Kelvin waves appear in the development of El Nino and the eastward waves convey anomalous downwelling signals of the thermocline, the SSTA amplitudes will be enhanced, which significantly promotes the development of El Nino, such as 1997/1998 El Nino; weak MJO-related Kelvin waves have little influence on El Nino events and such waves with anomalous upwelling signals will even hinder the occurrence and development of El Nino events. In general, MJO events in the western tropical Pacific have significant influence on El Nino events in some special cases, but they are not the key factors in the occurrence or termination of El Nino events.

关 键 词：季内振荡 开尔文波 厄尔尼诺 

分 类 号：P732[天文地球—海洋科学]