FY-4A辐射产品在贵州山区的检验与订正

Verification and Correction of FY-4A Solar Radiation Products in Guizhou Mountainous Areas

利用2018年3月12日—2019年2月28日贵州山区(从江、三穗、桐梓、贵阳、紫云、兴仁、威宁7站)地面太阳辐照度观测资料对FY-4A反演辐照度进行检验与订正分析。结果表明:(1)卫星反演辐照度取值范围比地面观测小,整体上反演辐照度偏高,晴空条件下反演精度远高于云条件下,正午偏差最小,下午偏差最大。(2)卫星反演辐照度与地面观测辐照度具有较为一致的日变化和季节变化,两者呈显著正相关,相关系数与海拔高度呈负相关。(3)平均偏差往往随着地面观测的增大而减小,当地面观测辐照度>800 W·m^(-2)时,反演辐照度往往偏小。(4)对地面观测辐照度进行阈值化后,用多元线性回归方法对反演辐照度订正,订正后的产品在贵州具有较好的适用性。

Based on the ground solar irradiance observation data of national meteorological stations(Congjiang,Sansui,Tongzi,Guiyang,Ziyun,Xingren and Weining stations)in the Guizhou mountainous areas from March 12,2018 to February 28,2019,this study tried to verify and correct the accuracy of FY-4A surface solar irradiance(SSI)products.The results show that:(1)The range of FY-4A SSI value is smaller than that of the ground observations.On average,the FY-4A SSI of each station is higher than that of ground observations,and the accuracy under clear sky conditions is much higher than that under cloudy conditions.The deviation is the smallest at noon and the largest in the afternoon.(2)The FY-4A SSI and the ground observed SSI have relatively consistent diurnal and seasonal variations.There is a significant positive correlation between the two,and the correlation coefficient is negatively correlated with altitude.(3)The average deviation tends to decrease with the increase of ground observation.When the ground observed SSI is greater than 800 W·m^(-2),the FY-4A SSI tends to be lower than that of ground observation.(4)After thresholding the ground observed SSI,the FY-4A SSI is corrected using multiple linear regression.The corrected product has good applicability in Guizhou.