Study on the Spatiotemporal Variation of Global Solar Radiation in Southwest China

基于1957~2017年西南地区气象观测资料，利用线性回归法、Pearson相关性检验法和Mann-Kendall突变检验法，本研究分析了该区域太阳辐射的时空分布特征及其影响因子，结果表明：(1) 观测期间西南地区年太阳总辐射每年以−1.14 MJ/m2的速度下降，但下降趋势不显著，太阳总辐射发生突变的年份是1995年。(2) 西南地区月平均太阳总辐射变化呈现单峰变化趋势；夏季太阳辐射最强，平均值为1476.51 MJ/m2，春季次之，平均值为1416.61 MJ/m2，冬季最弱，平均值为861.83 MJ/m2。(3) 西南地区太阳总辐射空间分布表现为西部最高，平均值为6880.06 MJ/m2，呈阶梯式向东部逐渐降低。(4) 总云量对太阳总辐射的影响程度最大，呈显著负相关；其次是大气水汽含量，呈显著负相关；能见度的影响程度最小，仅在夏季呈显著正相关。Based on meteorological observation data from 1957 to 2017 in Southwest China, this study analyzed the spatiotemporal distribution characteristics of solar radiation and its influencing factors using linear regression, Pearson correlation analysis, and the Mann-Kendall mutation test. The results indicate that: (1) Annual total solar radiation decreased at a rate of −1.14 MJ/m2 per year during the observation period, though this declining trend was not statistically significant. An abrupt change occurred in 1995. (2) Monthly total solar radiation exhibited a unimodal variation pattern. Summer recorded the strongest radiation (average: 1476.51 MJ/m2), followed by spring (1416.61 MJ/m2), with winter having the weakest (861.83 MJ/m2). (3) Spatially, total solar radiation was highest in western regions (average: 6880.06 MJ/m2) and gradually decreased eastward. (4) Total cloud cover exerted the strongest negative influence on total solar radiation, showing a significant negative correlation. Atmospheric water vapor mass demonstrated the second strongest significant negative correlation. Visibility had the weakest impact, exhibiting a significant positive correlation only during summer.