中国不同时间尺度地表太阳总辐射估算研究

Estimation of total surface solar radiation at different time scales in China

利用全国95个气象站点逐日地表太阳总辐射和日照时数资料,通过最小二乘法拟合回归建立地表太阳总辐射气候学计算模型。通过对比分析以日值和月值为起点的地表太阳总辐射计算模型的精度,确定了全国不同省份和区域的不同时间尺度(月、季节、生长季和年)地表太阳总辐射计算模型,并探讨了经验系数a、b值的分布及变化特征。结果表明,以日值和月值为起点建立的月、四季、生长季和年地表太阳总辐射计算模型精度无显著性差异,相对误差均低于8.5%,但以日值为起点的计算模型a、b值变异性更小。在以日值为起点建立计算模型的前提下,全国各地a、b值自西北部向南部减小,且从四季到生长季再到年尺度,随着时间尺度增大,a、b值振幅减小。根据不同省份年地表太阳总辐射计算模型经验系数a、b值,全国可划分为新甘蒙地区、青藏高原地区和中东部地区3个区域,分别确定了每个区域四季、生长季和年尺度下地表太阳总辐射计算模型。各区域不同时间尺度地表太阳总辐射计算模型均通过了显著性检验(p<0.01),其中青藏高原地区和新甘蒙地区模型相对误差低于8.0%,模拟精度较高。

Using the data of total surface solar radiation and sunshine hours of the 95 meteorological stations nationwide, the solar radiation calculation model was established by fitting regression with least squares method. By comparing and analyzing the accuracy of the surface solar total radiation calculation model starting from the daily value and the monthly value, the surface solar total radiation calculation model of different time scales(month scale, seasonal scale, growing season scale and annual scale) of various provinces and regions in China was determined and the distribution and variation characteristics of the empirical coefficients a and b were discussed. The results show that there is no significant difference in the accuracy of the calculation model of the surface solar total radiation among the month, the four seasons, the growing season and the annual solar radiation. The relative error for all models is less than 8.5%, but the calculation model with the daily value as the starting point is better due to the less variability of its coefficients a and b. Based on the daily value as the starting point, the empirical coefficients a and b decreases from the northwest to the south, and their amplitudes decrease from the four seasons to the growing season and then to the annual scale in different regions. According to the empirical coefficients a and b of the annual total solar radiation calculation model of each province, the country can be divided into three regions: the Xinjiang-Gansu-Inner Mongolia region, the Qinghai-Tibet Plateau region and the central-eastern region. The total surface solar radiation calculation model for three regions in each season, the four seasons and the growing season and the annual scale are determined. These models all pass the significance test(p<0.01), and the relative errors of the models are lower than 8.0% in the Qinghai-Tibet Plateau and the Xinjiang-Gansu-Inner Mongolia regions, showing higher simulation accuracy.