1961-2015年共和县阴晴天日数变化特征

利用青海省共和县气象局观测的1961-2015年总云量资料,采用线性倾向估计法、M-K检验法和滑动t检验法,分析了近55年来该地阴、晴天气日数的变化规律.结果表明,共和县年平均晴天日数呈不显著的减少趋势,四季平均晴天日数增减均不显著,春季晴天日数呈增多趋势,夏季、秋季和冬季的晴天日数均呈减少趋势;夏季晴天日数在1969年发生了增多突变,年、春季、秋季、冬季晴天日数未发生突变.年阴天日数以3.08d/10a的速度显著增多,秋季阴天日数呈不显著的减少趋势,春季、夏季和冬季的阴天日数均呈显著的增多趋势,其中阴天日数增多程度从大到小依次为春季、夏季、冬季;春季阴天日数在1985年发生增多突变,夏季和冬季阴天日数在2005年发生由少到多突变,秋季阴天日数未发生突变,年阴天日数在2009年发生增多突变.

Variation Characteristics of Cloudy and Clear Days in Gonghe County during 1961-2015

Based on the observation data of cloud of Gonghe weather station during 1961-2015,the change laws of cloudy and clear days in recent 55 year were analyzed by linear tendency estimation method,M-K test method and sliding t test method.The results showed that the annual average clear days were not significant decreasing trend,the average of the four seasons clear days were not significant increase or decrease,the spring clear days were increasing tend,the summer,autumn and winter clear days all showed a trend of decreasing.The clear days in summer occurred in 1969,from less to more,clear days of year,spring,autumn,winter not mutated.In cloudy days significantly increased at a speed of 3.08 d/10 a,there was a unsignificantly reduce trend of autumn cloudy days,the cloudy days of spring,summer and winter are significantly increasing trend,and the cloudy days increasing degree for spring >summer>winter.The cloudy days of spring had a mutation in 1985,the cloudy days of summer and winter had a mutation from less to more in 2005.The cloudy days in autumn had no mutation,the annual average cloudy days had mutation from less to more in 2009.