赤道太平洋潜流变化特征及其与异常海温东传  

Variable properties of the equatorial undercurrent in the Pacific and its anomalous warm water eastward propagation

作　　者：陈锦年[1] 吕新艳[2] 胡敦欣[2] 

机构地区：[1]中国气象局广州热带海洋气象研究所,广东广州510080 [2]中国科学院海洋研究所,山东青岛266071

出　　处：《水科学进展》2005年第6期792-798,共7页Advances in Water Science

基　　金：国家自然科学重点基金资助项目(40136010);青岛市科技局资助项目(02KJYSH-03)~~

摘　　要：应用TOGA-TAO实测海流资料(ADCP)和SODA同化海流和海温资料,分析探讨了赤道太平洋潜流的季节和年际变化特征,以及与赤道异常暖水东传的内在联系.揭示了El Nino事件中异常暖水东传的物理机制.结果表明,赤道太平洋潜流具有明显的季节变化和年际变化特征.潜流的垂直最大深度可由海表层至300～400m,其多年平均最大流速可达100 cm/s.潜流最大中心的纬向变化位置基本维持在160°W-130°W之间.在年际变化中,赤道潜流变化特征非常明显,尤其是在El Nino事件发生过程中,赤道潜流出现明显的加强现象.其最大流速可达140 cm/s以上.在西太平洋暖池区域次表层暖水东传之前,位于中东太平洋次表层的赤道潜流就已出现加强,其最大流速中心沿温跃层不断加强和东移,'引导'来自西太平洋暖池区域次表层的异常暖水向东传播.因此,可以认为西太平洋暖池区域异常暖水的东传与赤道潜流的强度和东传存在密切关系,也就是说在El Nino事件中,赤道潜流的变化是导致西太平洋暖池区域次表层异常暖水东传的重要机制.Based on the current measurement data from TOGA-TAO（ ADCP ） and the assimilation analysis results from SODA （simple ocean data assimilation analysis）, this paper analyzes and researches seasonal and annual variations of the Equatorial Undercurrent（EUC） in the equator Pacific, which are related to the warm water eastward propagation along the equatorial Pacific, and reveals that the physics mechanism of the anomalous warm water propagates eastward in the E1 Nino annual event. The result indicates that the seasonal and annual variation of EUC are very obvious. The vertical depth of EUC is from the sea surface to 300 - 400 meters. The mean biggest velocity of EUC can reach to 100cm/s along the equator. The longitude change of the biggest center of EUC is basically maintained between 130°W - 160°W. The annual change of EUC is very obvious too, and particularly in the period of E1 Nino event occurs, the EUC appears obvious strengthening phenomenon. Its the biggest zonal velocity components can reach above the 140 cm/s. The EUC in middle-east Pacific has began strengthen before the subsurface warm water eastward propagation from westem Pacific warm pool, and its the biggest zonal velocity components center is constantly strengthened along thermocline with eastward propagation, leading the anomalous warm water form the warm pool area in the westem Pacific eastward propagation. So, we can think that the relationship between the eastward gation of the anomalous warm water from the warm pool area in westem Pacific and the strength of EUC is very closely, propaalso in other words in E1 Nino event, the variation of EUC is leading to the important mechanism that the subsurface anomalous warm water of the warm pool area in the westem Pacific propagates eastward.

关 键 词：赤道潜流 异常暖水 EL Nino 太平洋 

分 类 号：P731.11[天文地球—海洋科学]