近50年贵州省雷暴气候特征分析

Analysis on Thunderstorm Climatic Characteristics in the Latest Fifty Years in Guizhou Province

利用贵州79个观测站1962—20¨年雷暴观测资料，采用经验正交函数分解（EOF）、小波分析和Mann—kendall检验，研究了贵州雷暴的气候变化特征。结果表明：全省雷暴活动西南向东北沿线逐渐减弱，东南向西北部减弱；根据EOF分析，雷暴异常空间分布主要有以下三类：全区一致型、纬向型、经向型，即同增同减、北多（少）南少（多）、东增（减）西减（增），以全区一致型表现最为明显，其方差贡献为66．16％；此外，年际变化存在8～10年长周期、2～3年短周期振荡变化，且自1986年发生突变，总体呈现减弱的趋势，尤其以90年代以来最为显著，并推测未来几年全省雷暴活动将持续维持在偏少期。

The thunderstorm climatic characteristics in Guizhou province were analyzed by using the methods of EOF, analysis of Wavelet and Mann-kendall based on the thunderstorm data from 79 observing stations from 1962 to 2011. The results showed that the thunderstorms decreased gradually from the southwest region to the northeast region, and decreased gradually from the southeast region to the northwest region. The analysis of EOF shows that the abnormal features of spatial distribution of thunderstorm are comprised in three types： types of entire area, latitude direction and longitude direction, i. e. , increasing and decreasing at the same time, increasing （decreasing） in the north and decreasing （increasing） in the south, increasing （decreasing） in the east and decreasing （increasing） in the west. And the type of entire area is obvious, whose variance ratio contribution is about 66.16%. In addition, the yearly variation periods of thunderstorms are about the short periods of 2 to 3 years, and the long periods of 8 to 10 years. Since the sudden change in 1986, thunderstorms have been decreased, particularly in the 1990s. From all the above, the annual variation of thunderstorms showed a sustained decreasing tendency in the next few years.