摘要
利用美国国家环境预报中心(NCEP)1994年6月格点资料,对我国东南部夏季风的发展和演变进行了分析,并且与夏季风发展正常的1979年的相应结果作了比较.研究结果表明:1994年6月我国东南部夏季风的推进十分异常,出现了2次突变性的北跳,在第一次北跳后季风发生了南退现象.在季风正常的1979年6月,季风只出现了1次北跳.与季风的2次北跳相对应,我国东南部与夏季风相联系的暖湿气团、雨带以及最大正涡度区也出现了2次突变性的北跳,而且时间上相当一致.1994年6月西太平洋副热带高压和对流层上层的南亚高压也出现了2次突变性的北跳,但其北跳时间要比我国东南部夏季风的北跳略早一些;南亚高压第一次北跳尚未跳上高原,南支西风急流仍然维持,亚洲环流形势仍然为冬季形势,南下强冷空气与华南、江南的夏季风交汇导致了华南、江南的暴雨.1979年6月西太平洋副热带高压和南亚高压只出现了一次北跳.
The evolution of Monsoon in the Southeast China during June 1994 is analyzed by using daily grid point data from American National Center for Environment Prediction(NCEP).The evolution of atmospheric circulation of summer monsoon during June 1979 is compared with that during June 1994. The results show that the onset and evolution of Monsoon in the Southeast China in 1979 were normal, whereas in 1994 they were abnormal. During June 1994, Monsoon in the Southeast China jumped northward twice. Corresponding to the two northward jumps of the Southeast China Monsoon, the isoline of θ se =340 K(or 336 K) on the 850 hPa surface, rain belt and the maximum positive vortex zone also jumped northward twice at almost the same time during June 1994.During June 1979,they only jumped northward once on 16th June.During June 1994,the Western Pacific Subtropical High and the Southern Asia High in the upper troposphere moved rapidly northward twice at the same time, which occurred earlier than two northward jumps of the Southeast China Monsoon respectively. The rapidly northward shift of the Western Pacific Subtropical High and the Southern Asia High occurred only once on 19th June,1979.
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
1999年第6期99-104,共6页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家攀登A"南海季风科学实验"资助项目
