天津盛夏降水趋势与初夏华北高压的统计分析

Statistical Analysis of Tianjin Precipitation in Mid-Summer and North China High in Early Summer

根据初夏 (6月 )的天气气候演变 ,预测盛夏 (7～ 8月 )的短期气候趋势 ,一直是急需解决的难题。文章揭示了自 195 8年以来天津盛夏降水趋势与初夏时节临近地区上空的环流特征之间的统计关系。结果表明 ,初夏华北高压强时盛夏天津降水偏少 ,反之盛夏天津降水偏多 ,不仅逐年的对应关系显著 ,而且变化趋势相反 ,转折时期也一致。初步解释了 2 0世纪 70年代以前天津 (华北 )盛夏多雨和 80年代至今天津 (华北 )少雨的物理原因。以此为主要根据建立了初夏对于盛夏天津降水的短期气候预测方法 ,1998～ 2 0 0 3年连续 6年预报正确。

The statistical relation between precipitation in mid-summer in Tianjin and circulation features over North China in early summer was analyzed. It is shown that when the North China High was stronger in early summer, the precipitation over Tianjin was less than normal in mid-summer, and vice versa. Furthermore, the causes for more-than-normal precipitation in mid-summer in Tianjin before 1980 and less-than-normal precipitation after 1980 were studied preliminarily. Hereby, a short-range climatic prediction method of precipitation in Tianjin by atmospheric circulation in early summer was developed, which performed well in the trial operation from 1998 to 2003.