摘要
利用ECMWFl979—1984年5个冬季(12—2月)的资料对东亚和西太平洋地区的冬季风进行了统计研究。得到的主要结果有: (1)东亚和西太平洋地区有两个冷涌区;从东海到南海等东亚沿岸地区和菲律宾以东西太平洋地区。其中以前者最明显。冷涌主要是700hPa以下的现象,近地面层北风最强,随高度迅速减弱。 (2)伴随着冷涌向南扩展,冷空气经华南沿中南半岛沿岸区一直向南扩展到近赤道地区; (3)在近地面层,西伯利亚高压的活动和强度与冷涌有密切的联系; (4)东亚的冬季风或冷涌有明显的年际变化,这与西伯利亚高压和南支槽活动的年际变化有关。
Utilizing the ECMWF datasets for 5 winters (Dec. thr. Fed. )from 1979 to 1 984 ,a statistical study of winter monsoons in East Asia and West -Pacific has been made. The main results have been obtained as follows:
(1) There are two regions of cold surges in East Asia and West-Pacific: the East China Sea and the South China Sea,and the Western Pacific to east of Phillipines. The former area isa major area of cold surge with high frequency of activity and great intensity . The cold surge is observed below 700hPa , with the north wind at its maximum near surface and rapidly decreasing with height.
(2) Accompanying the southward penetration of cold surge, the cold air may extend southward from South China across the coastal region of Indo-China Peninsula down to the near - e-quatorial region.
(3) Near the surface, the activity and intensity of Siberian highs are closely related to cold surges.
( 4) One may observe remarkable interannual variability of winter monsoon or cold surges in East Asia that may be associated with the interannual variability of Siberian highs and troughs on southern branch of westerlies.
出处
《热带气象》
CSCD
1990年第2期119-128,共10页
