印度洋大西洋上升流的长期变化及其与爱尔尼诺南方涛动的关系

用Ｘｉｅ和Ｈｓｉｅｈ从三十九年（１９５０－１９８８）Ｃｏａｄｓ月平均风应力资料算出的全球海洋Ｅｋｍａｎ层底垂直速度资料，分别对印度洋和大西洋的垂直速度场作ＥＯＦ分析。在３８４个模中集中讨论了前四个模，印度洋的四个模被发现均与Ｅｌｎｉｎｏ事件有关，模一与模二表现为Ｅｌｎｉｎｏ前后的剧降与剧升，（只是模二的位相较模一滞后半年）而模三与模四的位相与模一、二反相、时间振幅的曲线在Ｅｌｎｉｎｏ前达到正峰值，

THE LONG-TERM CHANGES OF UPWELLING IN THE INDIAN OCEAN AND ATLANTIC OCEAN ASSOCIATED WITH THE ELNINO-SOUTHERN OCILLATION

Using the COADS monthly wind stress (1960-1988) to compute the vertical Yelocity at the bottom of the surface layer, analysis of the wind-induced long-term anomalous upwelling/downwelling in the Indian ocean and the Atlantic ocean was carried out by Empirical orthogonal functions and the composite methods. We found that the 4 EOF modes of the Indian ocean (accounting for 30.3% of the variances over the entire Indian ocean) and modes 3 & 4 of the Atlantic ocean (10. 1 % of the variances) were all associated with Elninos, each corresponding to a difference phase of an Elnino. The variation of time amplitude for those modes showed anomalously strong pulses and was accompanied with changes of the sign of Yertical velocity in an Elnino year. The range of change is 2~3 times of a normal fluctuation range. The first EOF mode of the Atlantic ocean(15.8gof the variances) is representative of a long-term oscillation that has a period of about 12 years. The second mode describes the continuous decrease of the strength of vertical velocity.The pattern of the first EOF resembles a zonal upwelling and downwelling for both oceans that,ar, symmetrical ahout the equator, but the second mode is antisymmetrical about the equator, the patterns of mode 1 and mode 2 show good similarity to the results of SST EOF analysis.