阿克苏地区近45年日照时数变化特征

根据阿克苏地区8个气象站近45年(1961-2005)逐月日照时数资料,建立阿克苏地区年日照时数序列,利用3年滑动平均、一元线性回归、Mann-Kendall、灰色预测等方法,全面分析阿克苏地区近45年来日照时数变化的基本特征。结果表明:年日照时数呈现增加趋势,其变化的倾向率为3.9 h/10 a;年日照时数近45年来极低值出现在1985年,最高值出现在2005年;春季和夏季日照时数呈增加趋势,但是夏季变化趋势不明显,未能通过显著性水平检验;秋季、冬季日照时数呈减少趋势,其变化倾向率分别为-0.4 h/10 a和-11.0 h/10 a,秋季未能通过显著性水平检验。年日照时数在1974年发生了突变,日照时数逐渐减少。建立灰色预测GM(1,1)模型对阿克苏地区2006-2010年的年日照数进行预测,发现在今后几年阿克苏地区的年日照时数将会有所增加,年日照时数在2010年达到2 923.2小时,但未能超过近45年来的极大值。

Variation of sunshine hour in recent 45 years in Aksu Prefecture

Sunshine hour is the most intuitionistic representation of radiation quantum.The change of sunshine hours affects the growth of plant,animal and the anthropogenic activity.In this paper,the series of annual sunshine hours in the Aksu Prefecture,Xinjiang,China,are developed using the sunshine hours data from 8 meteorological stations in the Aksu Prefecture during the period of 1961-2005.The basic features of sunshine hours are analyzed using the methods of 3-year moving average,linear regression,Mann-Kendall statistic,grey forecast,et al.The main results are as follows:(1) The annual sunshine hours in the area is increasing at the trend rate of 3.9 h/10 a.This kind of tendency appears mainly in spring and summer and the trend rates are 12.1 h/10 a and 3.1 h/10 a,respectively.However,the kind of tendency in autumn and winter is decreasing and the trend rates of them is-0.4 h/10 a and-11.0 h/10 a,respectively.(2) The annual sunshine hours in Aksu Prefecture can be classified into three stages and the years with the most and least sunshine hours occurred in 1985 and 2005,respectively.The fluctuation of spring and winter sunshine hours is not significant.However,the oscillation of summer and autumn ones is complex.May be it is because the summer rainless days have a downward trend.The downward trend of winter is probably due to dust-floating increasing in the atmosphere because large amount of coal has been consume by human being.(3) The predicted amount of sunshine hours from the established grey dynamic model indicates that there is an upward trend of the annual sunshine hours,but the trend is not significant.The sunshine hours changed abruptly in 1974,and then there is a relative less hours period,which is synchronous with temperature and precipitation trend at the same time.