中国东部水汽低频振荡的季节变化特征-气象研究与应用

文章信息/Info

Title:: Seasonal variation characteristics of water vapor low-frequency oscillation in eastern China

Author(s):: PAN Yi-ming¹; Li Hua-shi²; 1. Shangsi County Meteorological Service, Fangchenggang Guangxi 535500;
2. Chongzuo Municipal Meteorological Service, Chongzuo Guangxi 532200

Keywords:: water vapor low-frequency oscillation; seasonal characteristics; EOF; EEOF; wavelet analysis

摘要:: 利用NCEP多年日平均可降水量资料,进行EOF、小波分析和EEOF等分析,得到以下结论,在分布上,我国东部水汽低频振荡受水汽源地影响主要有着三种不同的地理分布形势:一是我国东部水汽低频振荡约以长江为界,南北具有相反的变化形势;二是不同的正负形势由北向南间隔分布,出现正负正或者负正负的形势;三是我国东部水汽振荡在空间上具有整体的一致性,绝大部分都是正异常或者负异常,各种形势随时间相互替换。在强度上,华南、东海、长江中下游地区强度比较大而且振荡活跃,夏季的振幅最大,振荡最明显,能量也最大,春秋次之,冬季的振荡能量最小,振荡最弱。在周期上,水汽低频振荡在春、秋和冬季都具有64天左右的振荡周期,而在夏季只有24天左右的振荡周期。

Abstract:: Based on analysis on the years of NCEP daily average rainfall data by the EOF, wavelet analysis and EEOF, the conclusions are that:from the distribution, water vapor low-frequency oscillation in the eastern part of China affected by water vapor source mainly was divided into three different kinds of geographical distribution:First, the north and south water vapor low-frequency oscillation, which are divided by the Yangtze river have opposite change form; Second, the change form is interval distribution from north to south, appearing positive-negative-positive or negative-positive-negative; Third, the water vapor oscillation has the space consistency with most being positive or negative anomaly and the situation replacing with each other over time. from the intensity, strength of oscillation in south China, east China sea and the middle and lower reaches of the Yangtze river region is greater and active, maximum amplitude, the most obvious oscillation and the biggest energy are in summer, spring and autumn rank second, and that of winter is least weakest. Periodically, there is 64 days of oscillation of water vapor low-frequency oscillation in the spring, autumn and winter, while in summer it is only 24 days.