中低纬海气相互作用的耦合型态及其年代际振荡特征研究

STUDY THE COUPLED PATTERN OF MIDDLE-LOW AIR/SEA INTERACTION AND ITS DECADAL VARIATION

采用北半球500 hPa高度场和北太平洋海温场月平均资料（1951～1995）,借助于SVD分析方法,对北太平洋地区海气相互作用的耦合型态的季节及其年代际变化特征作诊断分析。结果表明:（1）在大气-海洋相互作用过程中,与厄尔尼诺（或拉尼娜）事件有关的SST分布型起着重要作用,而与此耦合的大气则表现为类似于PNA型遥相关的变化。其中冬季（1月）海气相互作用的耦合程度较高,具体表现为厄尔尼诺事件对应着高度场的PNA流型。而与拉尼娜相对应的夏季500hPa高度场类似于东亚-太平洋（PJ）流型,但在4个季节中,夏季的海气相关耦合程度相对较差。春秋季同属于过渡季节,秋季海气之间的相关耦合不及春季紧密。（2）1976年前后海气耦合分布型态发生明显变化,冬季500hPa高度场的PNA流型加强,阿留申低压加深并向东南移动,1976年后的夏季500hPa高度场的PJ流型表现明显,而1976年前这个遥相关型并不显著。

This paper is concerned with seasonal and interdecadal variability of the coupled pattern of Tropical-midlatitude air-sea. The spatial patterns and their temporal evolution are picked up through the singular value decomposition (SVD) analysis. Result shows, the PNA teleconnection is closely connected with EL Nino and the patterns-Japan (PJ) teleconnection pattern is related with La Nina. The abrupt change of the coupled pattern in the middle 1970s. The SST in the central and eastern Tropical Pacific increase and SST in the middle Northern Pacific decrease significantly, PNA pattern in winter is strengthened. The further study demonstrated that the PJ pattern only obvious after middle 1970s.