新疆天山地区日照时数的气候特征

Climatic Characteristics of Sunshine Duration in the Tianshan Mountains of Xinjiang

基于1961-2008年新疆天山地区23站日照时数的逐日资料,使用一元线性方程和M-K检验等统计方法,分析天山地区日照时数的时空变化特征。结果表明:①日照时数的气候分布存在明显的空间差异,呈东多西少,南多北少的分布特征。②区域平均日照时数均呈减少趋势,尤其在冬季和夏季。③四季除春季外日照时数均存在明显的年代际变化特征,并发生了由多到少的气候突变,冬季在1987年,夏季在1978年,秋季在1980年左右。20世纪80年代中后期至今,冬、夏、秋三个季节日照时数减少的趋势显著。④冬季和夏季日照时数的较快减少与近20年来污染加重及云量增多有关。

Based on the daily sunshine duration data observed at 23 weather stations in the Tianshan Mountains during the period of 1961-2008,the spatiotemporal distribution and variation features of sunshine duration in the Tianshan Mountains were analyzed using some statistical methods,such as the simple linear regression and Mann-Kendall test.The results are as follows：（1） There was an obvious regional difference in climatic distribution of sunshine duration,and the sunshine duration increased from the west to the east and from the north to the south in the Tianshan Mountains;（2） The regional average sunshine duration was in a decrease trend,especially in winter and summer;（3） There was an obvious decadal variation trend of seasonal sunshine duration except that in spring,and a sharp decrease of seasonal sunshine duration occurred in winter 1987,summer 1978 and autumn 1980;（4） The sharp decrease of sunshine duration in winter and summer was related to the serious air pollution and the increase of cloud cover in recent 20 years.