摘要
本文利用1971—1988年各月逐日北半球500hPa高度场资料,对60°N上的阻塞高压活动进行了分析。结果表明,该纬圈上阻塞高压活动频率的纬向分布呈4波型,最大波峰值位于大西洋20°W处。阻塞高压季节变化最为显著的地区是大西洋东部、东欧至乌拉尔山、太平洋中部。阻塞高压活动类型有东进型、西退型和稳定型三类。其中稳定型阻高占55.1％。夏季以稳定型为主,秋冬以移动型为主。阻高活动平均维持期在11.5天,其中71％集中在8—13天之间,各区域阻高的长期变化存在着准两年振荡周期。
Based on the data of the.daily 500hPa in the Northern Hemisphere from 1,971 to 1988, the blocking.activities along 60°N is statistically analysed. The results show that the frequency of blocking activities in the latitu- dinal variation is characterized by four wave patterns and the position of the maximum wave peak is at the 20°W. The seasonal variation of blocking in the region of eastern Atlantic, central Pacific and from East-European to Urals is the most obvious. The blocking activities can be divided into three patterns, eastward and westward mobile, and stationary. The probability of the stationary blocking accounts for 55.1%. It is predominant in summer. On the cantrary, the blocking of the mobile pattern is predominant in autumn and winter. Its average living period is 11,5 days. The long-range variations of blocking in all regions show the period of quasi-biennial osciallation.
出处
《气象》
CSCD
北大核心
1990年第3期3-8,共6页
Meteorological Monthly
