近50年云贵高原楚雄市日照时数变化特征及其成因分析

Analysis of Variation Characteristics and Causes of Sunshine Duration at Chuxiong in Yungui Plateau in Last 50 Years

利用近50年云南省楚雄市气象观测站日照资料,采用线性倾向估计法分析了楚雄市日照随时间的变化特征,并使用统计分析软件对日照变化的影响因素进行了相关性分析。结果表明,近50年楚雄市日照时数年代际变化呈减少趋势;日照时数月变化为11月一次年4月多于5-10月,即干季多于雨季;日照时数最多的月份是3月,最少的是7月;对近10年日照时数日变化而言,14:00(北京时)日照最为充足。通过相关分析得到日照时数的变化与自然因子中的云量、雾日和年降水量呈负相关关系;与人为因子也呈负相关关系。

Basing on the meteorological data of sunshine duration at Chuxiong in the last 50 years,its temporal variation characteristics of sunshine duration are analyzed using the linear tendency estimate method,and the factors affecting the sunshine duration are analyzed using the Statistic Package for Social Science(SPSS) software.The result shows that in the last 50 years the annual sunshine duration at Chuxiong has been diminishing,and decreasing waved.It also shows that monthly sunshine duration variation is that the sunshine duration from November to April of the following year is more than that from May to October.So the sunshine duration in dry season is more than that in the wet season.The most sunshine hours appear in March,the least sunshine hours appear in July.In the past decade,the daily variation of sunshine duration shows that the most sufficient is at 14:00(Beijing time).Through some relative analysis,the variation of sunshine duration is obviously negatively with the cloudage,fog days and annual precipitation of natural factors,and weak negative correlation with human factors.