1951-2013年格尔木及周边地区日照时数气候变化特征分析*

利用柴达木盆地格尔木站及周边9个气象站近60a逐月、年日照时数、气温、云量、降水、相对湿度资料以及1951~2013年西太平洋副高面积指数资料,通过统计学方法、突变检验、小波分析等方法,对格尔木日照时数的气候变化特征进行了分析。结果表明：近60a来格尔木日照时数变化总体呈下降趋势,春季变化较平稳,夏、秋、冬三季呈明显的减少趋势。月日照时数5月最多、2月最少。年代际变化上世纪50年代和60年代较为平稳,70年代突然下降,80年代又有所增加,90年代比80年代略有减少。到了本世纪头十年,平均日照时数急剧减少。日照时数具有明显的5年和7年短周期,日照时数在2006年出现突变。从研究结果来看,自然因子大气环流、气温、总云量、低云量、相对湿度等因素是格尔木及周边地区日照时数变化的主要影响因子,人工增雨为主的人类活动和三江源地区生态保护工程的实施对格尔木及周边地区日照时数也可能是影响因子,但这还有待进一步研究证实。

Analysis on the Characteristics of Sunshine Duration Change in Golmud Area from 1951 to 2013

By using the monthly, annual sunshine duration, temperature, cloud cover, precipitation, relative humidity data of the 9 meteorological stations in Qaidam Basin over 60 years,and the 1951~2013 years of West Pacific subtropical high area index data, the characteristics of sunshine dration climate change is analyzed,which the statistical method, mutation testing and wavelet analysis are used. The results showed that: the sunshine duration of Golmud over 60 years showed a trend of decline.and in spring, it is relatively stable, and in the other seasons it become significantly reduced. The most sunshine duration is in May and the least in February. Interdecadal variation of the last century 50"s and 60"s are more stable, 70"s suddenly dropped, 80"s and 90"s increased, slightly less than the 80"s, in the first decade of the 21st century,the average sunshine duration decreased sharply. Sunshine duration is obvious for 5 years and 7 years of short cycle, the abrupt change of climate appeared in 2006. The main facters that influenced sunshine duration are atmospheric circulation, temperature, total cloud, low cloud cover and relative humidity.It may be that the weather modification and the ecological protection project of Sanjiang source region are the impact factor, but this has to be confirmed by further studies.