赤道印度洋海温偶极子型振荡及其气候影响  

The Dipole in the Equatorial Indian Ocean and Its Impacts on Climate

作　　者：李崇银[1] 穆明权[1] 

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029

出　　处：《大气科学》2001年第4期433-443,共11页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展规划项目G1998040903;国家自然科学基金资助项目49823002共同资助

摘　　要：对近百年观测资料的分析表明赤道印度洋海温（ＳＳＴ）确实存在着偶极子型振荡的变化特征，它在９～１１月最强，而在１～４月最弱；年际变化（４～５年周期）和年代际变化（主要为２０～２５年周期）也十分清楚。这个偶极子主要有正位相型（海温西高东低）和负位相型（海温东高西低）；一般正位相型的振幅强于负位相型。尽管在极个别年赤道印度洋海温偶极子似乎与太平洋ＥＮＳＯ无关，但总体而论，赤道印度洋海温偶极子与赤道太平洋海温偶极子（类似ＥＮＳＯ）有很好负相关。它们的联系主要是赤道大气纬向（Ｗａｌｋｅｒ）环流。资料分析表明，赤道印度洋海温偶极子与亚洲南部流场、青藏高压和西太平洋副高都有明显关系，表明它对亚洲季风活动有重要影响。The analyses in observational data of near 100 years showed that the variation of SST in the equatorial Indian Ocean has a feature of the diople oscillation: It mainly shows a positive phase pattern (higher SST in the west and lower SST in the east) and a negative phase pattern (higher SST in the east and lower SST in the west), the amplitude of the positive phase is larger than that of the negative phase. The dipole is stronger in September- November and weaker in January- April. It also has interannual variation (4- 5 year period) and interdecadal variation (25-30 year period). Although the Indian Ocean dipole in the individual year seems to be independent of the ENSO in the equatorial Pacific, in general, the Indian Ocean dipole has obviously negative correlation with the Pacific Ocean dipole (similar to ENSO). The atmospheric zonal (Walker) circulation is fundamental to relate the two dipoles. The data analyses still showed that the lower tropospheric wind fields over the southern Asia, the Tibetan high in the upper troposphere and the subtropical high over the northwestern Pacific are all related to the Indian Ocean dipole, which shows the important impact of the Indian Ocean dipole on the Asian monsoon activities.

关 键 词：印度洋 海表水温异常 偶极子型振荡 气候影响 季风活动 亚洲 大气环流 西太平洋副高 

分 类 号：P461.2[天文地球—大气科学及气象学]