ENSO期间热带西太平洋势能的年际变化

Interannual Variabilities in Potential Energy in the Western Tropical Pacific Ocean During an ENSO Event

利用1986/1987ENSO事件前后的深水CTD资料,计算了热带西太平洋(141°~165°E,10°N^10°S)相对于不同等压面的势能空间分布和时间变化。结果表明,ENSO期间热带西太平洋单位面积上水柱的势能明显减小,而热带西太平洋势能的经向变化明显大于纬向变化。经向变化的特征是赤道外势能大于赤道上的势能。势能最大值位于4°N和4°S,而最大年际变化则发生于7°N,远大于赤道附近。最后,还分析了热带西太平洋势能分布的地域性特征,并指出了这些特征与海洋水文特征的联系。

In this paper, the deep casting CTD data collected around the 1986/1987 ENSO event in the western tropical Pacific Ocean（141°～165°E, 140°～100°W）are used to calculate the spatial and temporal variabilities in potential energy relative to different isobaric surfaces in the sea area. It is shown from the calculation results that the potential energy in a water column above a unit area in the western tropical Pacific Ocean decreased significantly during the ENSO event, and the longitudinal variabilities in the potential energy in the western tropical Pacific Ocean are greater than the latitudinal ones. The characteristics of the longitudinal variability are that the potential energy in the extra-equatorial area is greater than that at the equator, the maxima of potential energy are located at 4°N and 4°S, respectively, and the greatest interannual variability of potential energy occurs at 7°N, which is much greater than that at the equator. Finally, the regional characteristics of potential energy in the western tropical Pacific Ocean are analyzed, and it is pointed out that these characteristics are associated with the marine hvdrogranhic feature in the sea ares.