福建省近60年日照时数时空变化特征及未来趋势分析

Analysis on the dynamic characteristics of sunshine duration of Fujian Province in the past 6 decades and its future trend

利用福建省22个气象站点近60年日照时数资料,通过线性倾向估计、滑动t检验、重标极差法(R/S)和经验正交函数(EOF)分解等方法对福建省1961—2018年日照时数的时空变化特征及未来趋势进行分析.结果表明:福建省平均日照时数为1739 h,日照时数整体呈下降趋势,下降速率为每10年62.28 h;平均日照时数以夏季最大,春季最小,四季最大日照时数均出现在20世纪60—70年代;日照时数在1971年、1986年发生突变,1971年之前日照时数呈明显的上升趋势,1986之后呈下降趋势;福建省日照时数序列具有长期相关的持续性,未来变化趋势与过去一致,四季和年际日照时数循环长度分别为6、7、4、6和8年;福建省日照时数占主导地位的分布为一致型,易出现一致偏多或一致偏少;第二种分布为东北—西南型.

Based on sunshine hours data in the growing seasons from 1961 to 2018 from 22 meteorological stations across Fujian Province,linear tendency estimation,sliding t-test,rescaled range analysis(R/S),and empirical orthogonal function(EOF)decomposition were applied to analyze the spatiotemporal change characteristics and future trends of sunshine hours in Fujian.The results showed that average sunshine hours in Fujian reached 1739 h,showing a downward trend at a rate of 6.228 h·a-1.Average sunshine hour duration peaked in summer and bottomed in spring,with the longest sunshine hours for 4 seasons occurring from the 1960s to 1970s.Sudden changes in sunshine hour arose around 1971 and 1986,which was before 1971,sunshine hours showed a distinctive upward trend,while after 1986,they changed into a downward trend.The series of sunshine hours in Fujian has a longterm correlation,and future changes were consistent with the pattern in the past.Seasonal and inter-annual cycle lengths of sunshine hours were 6,7,4,6 and 8 a,respectively.The primary distribution type of sunshine hours in Fujian was holistic,which was likely to be commonly more or commonly fewer.The second distribution pattern was northeast-southwest type.