摘要:
利用一个斜压两层海洋模式解析地研究了赤道东、西太平洋对信风张弛的响应特征.研究表明:当赤道上空偏东信风张弛或转为西风时,由于打破了海洋原来的平衡关系,结果在赤道东、西太平洋的温跃层附近产生了扰动并开始传播.西太平洋温跃层附近的扰动向东传播的速度远大于东太平洋扰动向西传播的速度,而且与东太平洋温跃层扰动向西传播的狭窄范围和小振幅相比,西太平洋温跃层扰动向东传播的范围和强度均很大.这与最近几次强厄尔尼诺增暖事件暖水从赤道西太平洋向赤道中、东太平洋的迅速传播特征是一致的.
Abstract:
In general,El Niño refers to the appearance of unusual high sea surface temperature in the eastern tropical Pacific Ocean.But in recent El Niño events(for example,1982/1983 and 1986/1987),the warm sea surface temperature anomaly first appears in the western Pacific Ocean and then expands eastward.That is to say,the El Niño events are not only confined to the eastern tropical Pacific Ocean.Based on the above facts,a baroclinic two layers ocean model is developed and used to study the responding characteristics of equatorial eastern and western Pacific Ocean to relaxation of trade winds.The results show the responding features are different due to the different physical processes off the coast of the eastern and western Pacific Ocean.In the western Pacific Ocean,when the westward trade winds relax,a eastward propagating wave quickly develops.At the same time,a westward traveling wave also excites in the eastern Pacific Ocean,but nomatter how the speed and amplitude,the eastward propagating wave is bigger than the westward traveling one,the eastward wave can rapidly affect on the central part of the Pacific Ocean,i.e.,the western Pacific Ocean is easy to be the source of El Niño events,especially the strong El Niño events.
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