摘要
经研究发现平流层东风波振荡主要发生在10～6月,活跃期为9个月,北上最高纬度达25°～30°N。东风波北上振荡时,如遇南下中低纬超长波西风槽时,可并入槽中东移不再西传。东风波振荡与赤道东西风活动周期直接有关。东西风都有准半年、准一年周期,西风有准两年周期,而东风没有准两年周期。西风周期时,东风波振荡活跃,东风周期时东风波南下赤道或进入南半球。东风波活跃位置偏东时,台风位置亦偏东我国受影响小降水偏少。东风波弱位置偏西时,台风位置亦偏西对我国影响大降水多。
The following facts are found in this paper. The easterly wave oscillation mainly occurs in October. June and, the highest latitudes it reaches northward are 25°~30°N. When the easterly wave moves nortward, it would merge into the ultru-long wave trough which moves southward from the middle and low latitudes, and then moves eastward.
The east wind and west wind oseillations have periods of quasi halfa year and quasi-one year; The west wind doesln't has quasi-Biennial oseillation, but the east wind has not. When the west wind prevails, the easterly wave is in great activity. When the east wind prevails, the easterly wave moves southward to the equator or into the Southern Hemisphere. When the easterly wave leans to east, the typhoon is to the east, then the precipitation is less than the normal over China. When the easterly wave is weal: and leans to west, the typhoon is to the west, then the precipitation is more than the normals over China.
出处
《海洋预报》
北大核心
1990年第4期37-48,共12页
Marine Forecasts
