甘肃省近35年连阴雨天气气候特征分析

利用1967～2001年甘肃省80个气象站的逐日降水资料对连阴雨特征进行了较全面的分析.结果表明：甘肃省连阴雨分布的特点是自西北向东南呈台阶状增加,连阴雨相对比较多的地区为甘南地区、陇南东部和陇东东部地区,在甘肃中部-天水-武都一带相对形成一个南北向的少连阴雨带.区域性连阴雨过程的月、季特征表明,夏季区域性连阴雨过程最多,秋季次之,春季和冬季最少.年代际变化特征表明春季区域性连阴雨次数从20世纪70年代到90年代变化不大,但夏秋季连阴雨次数,70年代明显偏多,80年代之后总体次数减少幅度较大.最后从不同季节形成的连阴雨环流形式进行了分析.

Climate feature of steady raining during past 35 years in Gansu province

With the daily precipitation data of 80 meteorological stations in Gansu province between 1967 and 2001 the climatic feature of the steady raining is analyzed. The result shows that the steady raining distribution increases dramatically from northwest to southeast in Gansu province. The analysis of the month-season feature of the large scale steady raining weather shows that the longer process is in summer and the shorter ones are in autumn and winter. The steady raining frequency is stable in spring between 1970s and 1990s and decreasing in summer and autumn between 1970s and 1990s.