热带气象学报2017，Vol.33Issue(4)：467-477,11.DOI:10.16032/j.issn.1004-4965.2017.04.004
两类El Ni(n)o对应的印度洋偶极子事件的比较研究
COMPARING STUDY ON INDIAN OCEAN DIPOLE EVENTS ASSOCIATED WITH TWO TYPES OF EL NI(N)O
摘要
Abstract
Based on various reanalysis data of the atmosphere and sea,the mechanism of warming in tropical Indian Ocean and ocean-atmosphere coupled process between the IOD events that co-occur with the EP and CP El Ni(n)o in summer and autumn from 1951 to 2012 are studied using composite analysis and a 2.5 layer dynamic upper-ocean model.The result shows that the intensity and region of positive sea surface temperature anomoaly (SSTA) in tropical Indian Ocean have great diversity between EP El Ni(n)o (EP-IOD)and CP El Ni(n)o (CP-IOD) in summer and autumn.Positive SSTA of EP-IOD first appears in the tropical northwestern Indian Ocean in summer and then extends southeastward to the central Indian Ocean south of the equator in autumn with increased intensity.While CP-IOD has a maximum positive SSTA mainly in the central Indian Ocean south of the equator in summer and autumn which is distributed east-west belt-shaped with weaker intensity compared with EP-IOD.Further analysis shows that,positive SSTA in tropical northwestern Indian Ocean in summer may be primarily caused by weak southwest summer monsoon through a vertical entrainment mixing process during EP-IOD.In autumn,easterly wind anomalies,which lead to entrainment positive anomaly,play a key role in maintaining positive SSTA in tropical northwestern Indian Ocean.Positive SSTA in the middle-south of tropical Indian Ocean mainly results from a warm Rossby Wave.By comparison,the evolution of warming in the middle-south of tropical Indian Ocean during CP-IOD is mainly associated with strongly anomalous northwestern wind which weakens easterly monsoon in summer and autumn.Besides,the warm Rossby Wave excited by abnormal anticyclone over the tropical southeastern Indian Ocean really counts.关键词
两类El Ni(n)o/印度洋/IOD/季节演变/2.5层简化海洋模型Key words
two types of El Ni(n)o/Indian Ocean/IOD/seasonal evolution/2.5 layer dynamic upper-ocean model分类
海洋科学引用本文复制引用
钱景,李崇银,谭言科,桂发银,黎鑫..两类El Ni(n)o对应的印度洋偶极子事件的比较研究[J].热带气象学报,2017,33(4):467-477,11.基金项目
国家自然科学基金项目(41490642、41475070)共同资助 （41490642、41475070）
