北太平洋热含量的年代际变化特征及其与阿留申低压的关系  

Features of Interdecadal Variation of the North Pacific Heat Storage and Their Relation to the Aleutian Low

作　　者：程军[1] 于非[2] 蒲书箴[2] 郭品文[1] 

机构地区：[1]南京信息工程大学大气科学系,江苏南京210044 [2]国家海洋局第一海洋研究所

出　　处：《海洋科学进展》2004年第4期417-428,共12页Advances in Marine Science

基　　金：海外杰出青年基金项目---太平洋环流变异及其与西边界边缘海的相互作用(40028605)

摘　　要：使用经验正交函数(EOF)等方法,分析了北太平洋(20°～60°N,120°E～120°W)上层海洋热含量(HST)、海表面气压(SLP)、海表感热和潜热通量的年代际变化特征,并探讨了北太平洋HST与阿留申低压在年代际时间尺度上的关系。研究表明:第1特征向量能很好地代表北太平洋HST年代际尺度上的时间和空间变化特征。在近50a中,北太平洋HST具有明显的年代际变化特征,周期约为25a,其中在20世纪60年代中后期到90年代初存在一个较强的完整周期震荡。变化中心位于38°N左右的西北太平洋,且在155°W处向南延伸。根据北太平洋上层海洋HST的冷、暖异常和增、减热趋势,年代际背景场可分为冷态和暖态以及增热期和减热期。对比研究发现,在年代际尺度上,北太平洋上层海洋热含量的增、减热过程通过影响以西北太平洋为中心的海表热通量,进而对阿留申低压有一定的控制作用。热含量增热过程对应于弱的阿留申低压,减热过程对应于强的阿留申低压,阿留申低压的响应一般滞后热含量增、减热趋势变化1～2a。北太平洋年代际背景场对其年际变化有较强的调制作用,且这种年际变化跟ENSO事件有一定的对应关系。In this paper, the empirical orthogonal function (EOF) method is used to analyze the features of interdecadal variations of upper ocean heat storage (HST), sea surface air pressure (SLP), sea surface sensible heat flux and latent heat flux in the North Pacific (20°-60°N,120°E-120°W), and the relationship between HST in the North Pacific and the Aleutian low at the interdecadal time scale is also discussed. It is shown from the study results that the first eigenvector of EOF analysis can well represent the features of interdecadal HST variation in the North Pacific. In last about 50 years, the HST in the North Pacific had obvious interdecadal variation features with a period of about 25 years, and a complete periodic HST oscillation was found during the period from the late 1960s to the early 1990s. The center of the interdecadal variation was located at about 38°N in the northwestern Pacific, and was extended southward at 155°W. Based on the cold/warm anomaly and the increasing/decreasing tendency of upper ocean HST in the North Pacific, the interdecadal background field can be divided into cold/warm state and heat increasing/decreasing period. It is shown from the comparison study results that the interdecadal heat increasing/decreasining processes of upper ocean HST in the North Pacific have certain control over the Aleutian low by their impacts on the sea surface heat flux centered in the northwestern Pacific, the heat increasing process corresponds to the weak Aleutian low, the heat decreasing process coreesponds to the strong Aleutian low, and the response of the Aleutian low generally lags behind the heat increasing/decreasing variations by 1 to 2 months. The interdecadal background field of the North Pacific HST has strong modulation on its interannual variations, and this interannual variations have certain corresponding relation to the ENSO events.

关 键 词：北太平洋 年代际变化 HST 阿留申低压 海表热通量 

分 类 号：P722[天文地球—海洋科学] P732.6