摘要
从1955至56～1987至88年的33个冬季的14个突发性增温过程(简称SSW)中,选出5个最强的加以平均,分析了增温期及其前后期的平均环流特征。结果表明:(1)30hPa极点温度与30年平均温度距平值,增温期为17.1℃,前、后期分别为-4.7℃和-8.9℃。(2)在500hPa和50hPa高度场上,增温期比其前、后期波数都少,经向度较大。经向度发展和极涡分裂为二的现象首先出现在对流层。(3)5次SSW均属北太平洋增温,其相应的年份都是平流层由冬转夏,即季变“迟”的年份。
In this paper, the mean circulation characteristics during the period of pre-, warming- and post-stages for 5 strongest sudden stratospheric wanning cases selected from 14 cases have been analysed.
The results show:
(1) The temperature anomaly at the North Pole at 30 hPa level is 17.1 ℃ in the warming-stage; -4.7 ℃, pre-stage; and-8.9 ℃, post-stage, respectively.
(2) The wave number of the height fields at 500- and 50-hPa level during the warming-stage are less than the pre- and post-stage, the meridionality of the wave is larger.
The development of the meridional circulation and the splitting of the Polar Vortex occured at the 500 hPa level firstly.
(3) All of the 5 cases were North Pacific warmings and occured in the years of late seasonal transformation from Winter to Summer in stratosphere.
出处
《高原气象》
CSCD
北大核心
1990年第1期104-109,共6页
Plateau Meteorology
基金
国家自然科学基金
关键词
平流层
突发性增温
平均环流
极涡分裂
SSW
The sudden stratospheric warming
Mean circulation
The splitting of the Polar Vortex
