Upward longwave radiation (ULR) is an important element for climate change analysis. We calculated ULR using land surface temperature (LST), sea surface temperature (SST), and downward longwave radiation (DLR) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud and the Earth’s Radiant Energy System (CERES), along with broadband emissivity calculated using four multiple linear regression models designed to consider specific land-cover categories along with MODIS data and reflectivity data for 241 materials from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Our broadband emissivity values were compared with those of Wang et al. Journal of Geophysical Research: Atmospheres, 110(D11), (2005); all correlation coefficients were higher than 0.90 for the period from January to December 2016, and the root mean square error (RMSE) was 0.00750–0.00825. We then calculated ULR using the broadband emissivity and compared the results with CERES data, resulting in smaller errors relative to CERES than found by Wang et al. (2005). Furthermore, the calculated ULR compared with the observational data of Baseline Surface Radiation Network (BSRN) and the resultant statistical values of R(correlation coefficient), RMSE, and bias were 0.93, 21.22 W m⁻², and 0.29 respectively.

中文翻译：

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基于表面类型的上行长波辐射计算算法

向上的长波辐射（ULR）是气候变化分析的重要元素。我们使用地表温度（LST），海面温度（SST）和中分辨率成像光谱仪（MODIS），云和地球辐射能系统（CERES）以及宽带提供的向下长波辐射（DLR）数据计算了ULR使用四个多重线性回归模型计算的发射率，这些模型旨在考虑特定的土地覆盖类别以及来自先进星载热发射和反射辐射计（ASTER）的241种材料的MODIS数据和反射率数据。我们的宽带发射率值与Wang等人的进行了比较。地球物理研究杂志：大气，110（D11），（2005）；在2016年1月至2016年12月期间，所有相关系数均高于0.90，均方根误差（RMSE）为0.00750–0.00825。然后，我们使用宽带发射率计算ULR，并将结果与​​CERES数据进行比较，与CERES相比，误差要小于Wang等人的发现。（2005）。此外，计算的ULR与基线表面辐射网络（BSRN）的观测数据相比，R（相关系数），RMSE和偏差的统计结果分别为0.93、21.22 W m^-2和0.29。