盘县50年日照变化特征分析

Analysis of Characteristics of the Change of Sunshine Duration in 50 Years in Panxian

本文利用盘县气象观测站1961~2010年逐月日照时数,采用气候倾向估计法和Mann-Kendall气候检验方法,分析盘县50年来的日照变化特征。结果表明:盘县年平均日照时数为1617.1 h,以1978年的1930.1 h为最多,以1976年的1435.8 h为最少。月日照时数以4月的177.1 h为最多,10月的103.0 h为最少,月日照时数分布呈双峰形式。1~4月逐月增加,到4月份达到峰值,随后逐月减少,到6月份达到谷值,然后又逐月增加,8月份达到第二峰值,接着又逐月减少,到10月份降到最低值;但10月份之后,到第二年的2月份日照时数变化幅度不大。年日照时数略呈上升趋势,其气候倾向率为5.7 h/10 a,以上个世纪70年代增加最为显著。春、夏、秋、冬各季日照时数变化趋势不相同,春、夏季的日照时数呈下降趋势,秋、冬季的日照时数呈上升趋势。年日照时数突变发生在1983年,春季日照时数在1975年存在减少的突变,秋季日照时数在1993年发生增加的突变;夏季虽呈下降趋势,但无突变现象发生;冬季日照时数虽发生多次增加和减少趋势,但仍无突变现象发生。

In this article, the characteristics of sunlight change of Panxian in past 50 years are analyzed through Climatic trend estimation and Mann-Kendall Climatic examination with the sunshine duration in Panxian Meteorological Station from 1961 to 2010. The results show that the annual sunshine duration in Panxian is 1617.1 h, that the max sunshine duration as 1939.1 h appears in 1978, and that the minimum as 1435.8 h appears in 1976. Every year, the max monthly sunshine duration is 177.1 h in April and the minimum is 103.0 h in October. It takes shape as double peak. From January to April, the sunshine duration increases, and the max amplification appears from February to March;it tops to 46.9 h. As to June, the sunshine duration decreases;the max damping appears from May to June;it tops to 39.5 h. As to August, the sunshine duration increases again, and to October it decreases again. The change of sunshine duration from October to December is not obvious. The annual sunshine duration is on a rise as 5.7 h of 10 years, and the most outstanding rise appears in 1970 s. The change trend of sunshine duration of every season is different. It is on a declining curve in Spring and Summer, and on a rise in Autumn and Winter. There is a sudden change of annual sunshine duration in 1983, and the seasonal sudden change of sunshine duration appears in Spring of 1975 as decreasing and in Autumn of 1993 as increasing;In Summer, it decreases not so.