江苏省日照时数的气候特征分析

CHANGES OF SUNSHINE HOURS IN THE RECENT 40 YEARS OVER JIANGSU PROVINCE

利用江苏省内66个气象站1960—1999年日照时数实测资料,分析了江苏省日照时数的气候变化趋势。结果表明,就整个江苏省平均而言,尽管在1960—1999年期间,省内年平均温度升高了0.6℃,但日照时数却呈明显的下降趋势;20世纪80—90年代年平均日照时数较60—70年代的平均值下降了164.7 h,下降幅度为7.35%;日照时数的下降主要表现在夏季和冬季,秋季和春季不明显;对日照时数气候变化的空间分析表明,局部地区与整个省域的气候变化趋势并不完全同步,大部分地区是下降的,个别地区则是上升的。

Utilizing the data of the monthly sunshine hours obtained from 66 meteorological observation stations over the Jiangsu province in 1960--1999, the climate trends of sunshine hours have been analysed. The result indicates that, in terms of the average of the whole province, the sunshine hours present obvious downtrend in spite of the fact that the annual average temperature has increased 0.6 ℃ during 1960--1999. In comparison with the 1960 s--1970 s, the annual average sunshine hours of 1980s--1990s has decrease 164.7 hours or 7.35%. Over the past 40 years, the rate of sunshine hours has decreased steadily especially in summer and winter. Spatial distribution of the change rate shows that this trend is general but not universal,most of the area has decreased but a few has increased.