近50年青海省贵德县日照时数变化规律(英文)

The Change of Sunshine Duration in Guide County,Qinghai Province in Recent 50 Years

对近50年贵德县日照时数的年、季和月变化特征及其与云量、降水的关系进行了分析,并用Mann-Kendall气候突变理论对日照时数进行检测分析。结果表明,近50年贵德县年日照时数总体上呈减少趋势,年际变化幅度较大,峰值点(1963年)与谷点(1975年)相差可达357.5h;日照时数存在明显的季节差异,各季季日照时数年际变化减少的趋势从大到小依次为夏季>冬季>春季>秋季;相应各月日照时数除4、5、11月呈微弱增加趋势外,其他各月均呈减少趋势;2～7月的日照时数与总云量变化极为一致,秋冬季日照时数与总云量变化相反;年降水量的谷值年份和日照时数的峰值年份一一对应,存在着显著的负相关关系。

The annual,seasonal and monthly variation of sunshine duration and its relationship with cloudiness and precipitation in recent 50 years were analyzed in Guide County,and sunshine duration was detected and analyzed under Mann-Kendall climate sudden change theory.The results showed that annual sunshine duration generally had a decreasing tendency over the last 50 years with large annual variation range,and there was a difference of 357.5 h between peak point(1963) and valley point(1975).Sunshine duration changed obviously with seasons,and the sequence of seasonal sunshine duration was summer > winter > spring > autumn.Sunshine duration had a slight increase in April,May and November and a decrease in other months.The sunshine duration change was in good agreement with total cloudiness from February to July,while the sunshine duration changes in autumn and winter had an opposite tendency with total cloudiness.Meanwhile,there was a significant negative correlation between annual precipitation and sunshine duration,the valley of annual precipitation and the peak of sunshine duration occurred in the same year.