Accuracy assessment of three remote sensing shortwave radiation products in the Arctic

In this study, the shortwave radiation data in 2007 from GEWEX-SRB, ISCCP-FD and CERES-SYN radiation products were evaluated against ground observations from BSRN, CEOP and GC-Net in the Arctic. The evaluation result shows that the accuracy of the three shortwave radiation products in the Arctic is low. In the Arctic Region, CERES-SYN radiation product quality is superior to GEWEX-SRB and ISCCP-FD. The RMSEs and MAEs of the three shortwave radiation products are > 20 W/m2 at most sites. The mean RMSE and MAE of the downward shortwave radiation data of CERES-SYN are 54.4 W/m2 (42.9%) and 28.4 W/m2 (23.0%), respectively, the mean RMSE and MAE of the upward shortwave radiation data are 50.8 W/m2 (80.4%), 28.4 W/m2 (41.3%). The indexes values of the other two products are greater than CERES-SYN. Through accuracy analysis, it can be concluded that there are seasonal shortwave differences between satellite-estimates and ground measurements. The error sources are mainly systematic errors, rather than random errors. The main factors that affect the accuracy of the flux data include the spatial heterogeneity of the surface, the influence of the cloud, the accuracy of input inversion parameters and the low spatial resolution of the radiation products.