海陆纬向非均匀热力结构与跨赤道气流和温带西风急流分布的关系

THE CORRELATION BETWEEN THE THERMAL STRUCTURE OF LONGITUDINAL INHOMOGENEITY OF SEA AND LAND AND DISTRIBUTION CHARACTERISTICS OF CROSS-EQUATORIAL FLOW AND MID-LATITUDE WESTERLISE

用数值模拟方法,研究海陆热力结构季节变化对经圈环流、南北半球西风轴以及急流中心的影响。数值试验得到如下结果:(1)海陆纬向非均匀加热结构不仅有利于跨赤道气流的加强,而且形成跨赤道气流高、低层反向特征;(2)海陆纬向非均匀结构使模拟到的北半球西风急流更接近实况。说明南北半球海陆热力强迫不仅是全球跨赤道气流通道形成的重要原因,而且影响北半球西风急流的强度和分布。

It is suggested in this paper that thermal forcing of sea and land of the two hemispheres may be an important cause of the formation of the cross-equatorial flow. The numerical experiments show that thermal structure of longitudinal inhomogeneity is not only advantageous to the intensification of cross-equatorial flow, but also results in the inverse characters between high and low level. In this paper, the correlation between ageostrophic flow and middle-latitude westerlies distribution is studied. The effects on westerlies of seasonal variation of thermal forcing structure and discussed.