四川盆地日照时数变化特征及未来趋势分析

Characterization of Changes in Sunshine Hours and Analysis of Future Trends in the Sichuan Basin

摘要: 基于1980~2018年14个气象站点实测的日照时数，采用线性倾向趋势分析、Morlet小波分析和重标极差分析方法分析了四川盆地日照时数时空分布特征及其未来变化趋势，结果表明：1) 观测期间年日照时数呈增加趋势，气候倾向率达到了19.1 h/10a，且春夏冬三季呈增加趋势，秋季呈下降趋势，但这些变化均没有达到显著性水平。年日照时数具有26年(第一主周期)和8年(第二主周期)的周期变化特征。2) 年日照时数在中部及西南地区较低，由此向北和向西均逐渐增加；夏季日照时数自西南向东北日照时数值呈逐渐增加趋势，而冬季的空间分布模态与夏季基本相反。3) 年日照时数未来变化继续呈增加趋势，但这种持续性较弱。季节尺度上春夏冬三季的日照时数继续呈增加趋势，而秋季日照时数未来趋势存在很大的不确定性。

Abstract: Based on the sunshine hours measured by 14 meteorological stations from 1980~2018, this paper studies the temporal and spatial variation characteristics and its future trend in the Sichuan Basin by using linear trend analysis, Morlet wavelet analysis and re-scale range analysis. The results showed that: 1) during the observation period, the annual sunshine hours showed an increasing trend, and the climate trend rate reached 19.1 h/10a. In addition, there was an increasing trend in spring, summer and winter, and a decreasing trend in autumn. But none of these changes reached a significant level. Annual sunshine hours had periodic changes of 26 years (the first main cycle) and 8 years (the second main cycle). 2) The annual sunshine hours were lower in the central and southwest regions of the Sichuan Basin, and thus gradually increased north and west; the sunshine hours in summer gradually increased from southwest to northeast, and the spatial distribution mode in winter was basically opposite to that in summer. 3) Future changes in annual sunshine hours continued to show an increasing trend, but this persistence was weak. On the seasonal scale, sunshine hours in spring, summer and winter continued to increase, while there is a great deal of uncertainty about future trends in fall sunshine hours.