Abstract:

Based on the monthly sunshine duration data from 1961 to 2010 collected from 121 meteorological observation stations in Yunnan Province, the spatial-temporal variation characteristics of seasonal sunshine duration in Yunnan Province in recent 50 years were analyzed by using the method of linear trend analysis. The main results are as follows: In the last 50 years,  the average sunshine duration in spring was longest, and in winter it was the second, it was longer in autumn than that in summer. In four seasons the longest sunshine duration distributed in the central and west region of Yunnan. Average sunshine duration in four seasons presented a decreasing trend, which reduced fast in spring, then in summer, winter and autumn. Sunshine duration in four seasons declined fastest in the north of central Yunnan along the Jinsha River basin, while the fastest growth areas were Pu’er and Baoshan. Correlation analysis showed that the zonal wind was a major factor affecting the duration of sunshine.

Key words:  sunshine duration, low latitude plateau, trend analysis, correlation analysis

摘要：

利用云南121个气象站1961~2010年日照时数逐月观测资料，采用线性趋势分析等方法分析近50 a云南日照时数的四季时空变化特征。结果表明：近50 a来，云南四季平均日照时数春季最长，冬季次之，秋季大于夏季；四季中最长日照都在滇中及其以西地区。四季平均日照呈减少趋势，其中春季减少最快，夏季次之，冬季大于秋季。四季日照时数减少趋势最快的区域在滇中以北金沙江流域一带，增加最多的区域为保山和普洱，整体上日照时数以减少趋势为主。相关分析表明纬向风是影响日照时数的重要因子。

关键词: 四季日照, 低纬高原地区, 趋势分析, 相关分析