1958年初夏北半球对流层上部大气环流演变的分析

本文利用1958年5月下旬至7月初北半球的对流层顶图,分析这段时期内大气的结构,以及副热带急流和副热带高压的变化,得到以下一些事实:(1)在初夏大气的三折结构也是很清楚的。对流层顶图在夏季仍可以作为分析对流层上部环流情况的一个工具。(2)在这段时期内,副热带急流在全球范围一般有6—7个波,波动振幅和波数呈有规律的循环变化,一循环约15天左右。(3)副热带急流的平均纬度在这段时期内有了显著的季节性北移,北移不是逐渐的而是集中在6月初和6月底副热带急流波动振幅加大的时候。(4)200毫巴上副热带高压轴线的北移与副热带急流的北移是一致的。

A SYNOPTIC ANALYSIS OF THE EVOLUTION OF GENERAL CIRCULATION IN THE UPPER TROPOSPHERE OF THE NORTHERN HEMISPHERE DURING THE PERIOD OF EARLY SUMMER, 1958

The structure of atmosphere and the evolution of the subtropical jet and subtropical high during the period May 22-July 3, 1958, are studied by means of tropopause map. The following facts are obtained: (1) The three-fold structure of atmosphere is also rather clear in the early summer, hence tropopause maps can still be used in Summer in analysing the general circulation in the upper troposphere. (2) During this period, there are six or seven waves on the subtropical jet over the hemisphere. The amplitude and number of waves change periodically with a period of about 15 days. (3) There is a sudden northward shift of the subtropical jet at the beginning and end of June when the amplitude of subtropical jet waves increases. (4) The northward shift of the axis of the subtropical high at 200 mb is consistent with the northward shift of the subtropical jet.