The Kelvin Wave Processes in the Equatorial Indian Ocean during the 2006-2008 IOD Events  

作　　者：DU Yan LIU Kai ZHUANG Wei YU Wei-Dong 

机构地区：[1]State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology Chinese Academy of Sciences, Guangzhou 510301, China [2]First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China

出　　处：《Atmospheric and Oceanic Science Letters》2012年第4期324-328,共5页大气和海洋科学快报（英文版）

基　　金：supported by the National Basic Research Program of China(973 Program,2010CB950300 & 2012CB955603);the National Nature Science Foundation of China(41176024,41176023,& 41149908)

摘　　要：The present study investigates the role of Kelvin wave propagations along the equatorial Indian Ocean during the 2006-2008 Indian Ocean Dipole(IOD).The 2006 IOD lasted for seven months,developing in May and reaching its peak in December,while the 2007 and 2008 IODs were short-lived events,beginning in early May and ending abruptly in September,with much weaker amplitudes.Associated with the above IODs,the impulses of the sea surface height(SSH) anomalies reflect the forcing from an intraseasonal time scale,which was important to the evolution of IODs in 2007 and 2008.At the thermocline depth,dominated by the propagation of Kelvin waves,the warming/cooling temperature signals could reach the surface at a particular time.When the force is strong and the local thermocline condition is favorable,the incoming Kelvin waves dramatically impact the sea surface temperature(SST) in the eastern equatorial Indian Ocean.In July 2007 and late July 2008,the downwelling Kelvin waves,triggered by the Madden-Julian Oscillation(MJO) in the eastern and central equatorial Indian Ocean,suppressed the thermocline in the Sumatra and the Java coast and terminated the IOD,which made those events short-lived and no longer persist into the boreal fall season as the canonical IOD does.The present study investigates the role of Kelvin wave propagations along the equatorial Indian Ocean during the 2006-2008 Indian Ocean Dipole （IOD）. The 2006 IOD lasted for seven months, developing in May and reaching its peak in December, while the 2007 and 2008 IODs were short-lived events, beginning in ear- ly May and ending abruptly in September, with much weaker amplitudes. Associated with the above IODs, the impulses of the sea surface height （SSH） anomalies reflect the forcing from an intraseasonal time scale, which was important to the evolution of IODs in 2007 and 2008. At the thermocline depth, dominated by the propagation of Kelvin waves, the warming/cooling temperature signals could reach the surface at a particular time. When the force is strong and the local thermocline condition is fa- vorable, the incoming Kelvin waves dramatically impact the sea surface temperature （SST） in the eastern equatorial Indian Ocean. In July 2007 and late July 2008, the downwelling Kelvin waves, triggered by the Mad- den-Julian Oscillation （MJO） in the eastern and central equatorial Indian Ocean, suppressed the thermocline in the Sumatra and the Java coast and terminated the IOD, which made those events short-lived and no longer persist into the boreal fall season as the canonical IOD does.

关 键 词：Kelvin wave IOD equatorial Indian Ocean MJO 

分 类 号：P461.2[天文地球—大气科学及气象学] O357.5[理学—流体力学]