高空纬向风准3.5年振荡特征

本文利用1968—1985年NMC客观分析700和200 hPa月平均纬向风，对其准3.5年振荡（SO）作了研究。发现其主要活动于180°—150°W南北太平洋及25°—35°N纬带上。其传播特征为赤道上向东、副热带基本向西而中纬向东；50°—90°E间经向传播不明显，而太平洋上向北。CEOF分析表明，其方差主要集中于第1，2分量。对其演变及与东太平洋赤道海温的SO分量间关系也作了研究。

Features of Quasi–3.5 Year Oscillation of Zonal Wind in Troposphere

Using the monthly zonal wind data at 700 and 200 hPa during 1968—1985 analyzed by NMC, the features of quasi–3.5 year oscillation are discussed. It is found that the oscillation is mainly in the sourthern and northern hemispheres of 180 o—150oW and in the belt of 25o—35oN. It moves eastward over the equator and the midlatitude, and moves westward over the subtropics. For the meridional propagation, it is northward over the Pacific and there is no obvious propagation direction over the region of 50 o—90oE. The results of CEOF analysis show that the variance of oscillation is mainly concentrated at the first and second main component. In this paper, the evolution of oscillation and its relation to the 3.5 year oscillation of SSTA in the equatorial eastern Pacific are also discussed