中文摘要：

利用美国Scripps海洋研究所联合环境数据分析中心（JEDAC）提供的120°E～80°W,20°N～20°S范围的太平洋次表层海温资料,插值获得热带太平洋地区的等20℃海温面深度资料。分析发现,就全年及四季而言,太平洋的等20℃海温面呈西深东浅的纬向分布,在西太平洋地区呈深-浅-深的经向分布,在东太平洋地区呈浅-深-浅的经向分布。太平洋等20℃海温面的方差变化存在三个大值区,分别位于暖池、赤道附近及其东南太平洋海域。等20℃海温深度面的准3～7年振荡是除去年循环之外的最显著振荡周期。等20℃海温深度距平信号的准3～7年振荡传播的回路,很好地反映了El Nio和La Nia事件循环的特征,从而从观测事实方面支持了ENSO循环概念模式图。

英文摘要：

Through interpolation,the 20 ℃ isothermal depth（20 CID） data was created from the Joint Environmental Data Analysis Center subsurface ocean temperatures.The variation of the 20 CID in the tropical Pacific area（20 °S～20 °N,120 °E～80 °W） was analyzed by the methods of power spectrum and filter analysis.In the whole year,the zonal distribution of the 20 CID in the Pacific shows a pattern of being deep in the west and shallow in the east;the longitudinal distribution in the West Pacific area presents a deep-shallow-deep pattern,and a shallow-deep-shallow pattern in the East Pacific area.Three high-value areas of the 20 CID variance appear in the warm pool,the area near Equator and the southeast Pacific area.The most significant period of oscillation,with the annual cycle excluded,is about 3～7a.The propagation circuit of the 20 CID anomaly in the 3～7 a period mainly reflects the feature of the El Nio and La Nia cycles,which supports with observational facts the concept of an ENSO cycle pattern diagram.