IOD和ENSO事件期间热带印度洋的海平面变化  

Sea level variation during IOD and ENSO event in the tropical Indian Ocean

作　　者：蒋水风 杜凌[1] 常怡婷 张守文[1] 

机构地区：[1]中国海洋大学海洋系,山东青岛266100 [2]北海舰队海洋水文气象中心,山东青岛266003

出　　处：《海洋环境科学》2014年第3期399-406,共8页Marine Environmental Science

基　　金：国家自然科学基金(41376008;40906002);973课题(2012CB417401);全球变化与海气相互作用专项(GASI-03-01-01-09)

摘　　要：利用1993～2010年卫星高度计数据分析热带印度洋海平面年际变化。结果显示：西南热带印度洋和苏门答腊—爪哇岛沿岸海平面变化显著,标准差可达8 cm。经验正交分解第1模态呈偶极子分布,与IOD（Indian Ocean Dipole,印度洋偶极子）和ENSO（El Nino-Southern Oscillation,厄尔尼诺和南方涛动）事件密切相关;第2模态呈＂三明治＂结构。IOD、ENSO事件共同发生期间海平面年际变化较IOD事件期间更为显著,IOD事件期间的海平面年际变化较ENSO事件期间强且范围广,ENSO事件期间的海平面年际变化则主要位于南热带印度洋。大气风场通过Ekman效应和斜压Rossby波影响海平面年际变化,且区域特征显著。洋盆尺度上,斜压Rossby的作用明显大于局地Ekman效应,前者能解释30%的海平面年际变化;仅在阿拉伯海和南热带印度洋中部,风场强迫的局地Ekman效应对海平面年际变化的影响更为显著。IOD和ENSO事件期间的风场与海平面年际变化有重要联系,使得ENSO事件期间的海平面年际变化偏南偏弱。The interannual sea level variations in the tropical Indian Ocean are studied by using the satellite altimeter data from 1993 to 2010. Sea level varies significantly in the Southwestern tropical Indian Ocean and along the coast of Sumatra-Java,and its maximum value can reach 8 cm. The first EOF（Empirical Orthogonal Function） mode exhibits the dipole mode,which is closely related to the ENSO（El Nino-Southern Oscillation） and IOD（Indian Ocean Dipole） events. The second mode has a＂sandwich＂pattern. The sea level variation when both IOD and ENSO occurred is more significant than IOD occurred. The IOD event plays an important role on interannual sea level variations than ENSO event. The remarkable sea level variations associate with IOD event illustrates in the whole tropical basin, while the ENSO＇s is mainly located in the southern tropical Indian Ocean. The Ekman effect and Rossby wave induced by atmospheric wind field affect the interannual sea level variations,and they present geographical distribution. Rossby wave can explain more than 30% of the sea level variation on ocean basin scale. Only in the Arabian Sea and the center area of the equatorial Indian Ocean,the local Ekman effect is more effective. The significant discrepancy of the interannual sea level variation is mainly caused by the different distribution of wind field.

关 键 词：热带印度洋海平面 年际变化 ROSSBY波 Ekman效应 IOD和ENSO事件 

分 类 号：P732[天文地球—海洋科学]