Variation in joint mode of the tropical Indian-Pacific Ocean thermodynamic anomaly  

作　　者：郑冬梅 张启龙 

机构地区：[1]Key Laboratory of Ocean Circulation and Wave, Institute of Oceanology, Chinese Academy of Sciences [2]Graduate School of Chinese Academy of Sciences [3]Marine Environmental Forecasting Central Station of Liaoning Province

出　　处：《Chinese Journal of Oceanology and Limnology》2010年第3期619-625,共7页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Basic Research Development Program of China (973 Program) (No.2006CB403606);the Knowledge Innovation Program of Chinese Adademy of Sciences (KZCX3-SW-215);Special Project for Marine Public Walfare Industry (No. 200705010)

摘　　要：Previous research has defined the index of the Indian-Pacific thermodynamic anomaly joint mode (IPTAJM) and suggested that the winter IPTAJM has an important impact on summer rainfall over China. However, the possible causes for the interannual and decadal variability of the IPTAJM are still unclear. Therefore, this work investigates zonal displacements of both the western Pacific warm pool (WPWP) and the eastern Indian Ocean warm pool (EIOWP). The relationships between the WPWP and the EIOWP and the IPTAJM are each examined, and then the impacts of the zonal wind anomalies over the equatorial Pacific and Indian Oceans on the IPTAJM are studied. The WPWP eastern edge anomaly displays significant interannual and decadal variability and experienced a regime shift in about 1976 and 1998, whereas the EIOWP western edge exhibits only distinct interannual variability. The decadal variability of the IPTAJM may be mainly caused by both the zonal migration of the WPWP and the 850 hPa zonal wind anomaly over the central equatorial Pacific. On the other hand, the zonal migrations of both the WPWP and the EIOWP and the zonal wind anomalies over the central equatorial Pacific and the eastern equatorial Indian Ocean may be all responsible for the interannual variability of the IPTAJM.Previous research has defined the index of the Indian-Pacific thermodynamic anomaly joint mode （IPTAJM） and suggested that the winter IPTAJM has an important impact on summer rainfall over China. However, the possible causes for the interannual and decadal variability of the IPTAJM are still unclear. Therefore, this work investigates zonal displacements of both the western Pacific warm pool （WPWP） and the eastern Indian Ocean warm pool （EIOWP）. The relationships between the WPWP and the EIOWP and the IPTAJM are each examined, and then the impacts of the zonal wind anomalies over the equatorial Pacific and Indian Oceans on the IPTAJM are studied. The WPWP eastern edge anomaly displays significant interannual and decadal variability and experienced a regime shift in about 1976 and 1998, whereas the EIOWP western edge exhibits only distinct interannual variability. The decadal variability of the IPTAJM may be mainly caused by both the zonal migration of the WPWP and the 850 hPa zonal wind anomaly over the central equatorial Pacific. On the other hand, the zonal migrations of both the WPWP and the EIOWP and the zonal wind anomalies over the central equatorial Pacific and the eastern equatorial Indian Ocean may be all responsible for the interannual variability of the IPTAJM.

关 键 词：tropical Indian Ocean tropical Pacific thermodynamic anomaly joint mode ENSO dipole 

分 类 号：P732[天文地球—海洋科学] P732.6