Comparison of the Surface Solar Radiation Budget Derived from Satellite Data with that Simulated by the NCAR CCM2

A comparison of the monthly mean shortwave surface radiation budget (SRB) obtained from the World Climate Research Program (WCRP) shortwave global dataset with that simulated by the National Center for Atmospheric Research Community Climate Model version 2.0 (CCM2) is presented. WCRP/SRB data are derived from the International Satellite Cloud Climatology Project (ISCCP) C1 data using the Pinker algorithm. Large differences are found in monthly mean surface solar fluxes. The largest discrepancies are found in the summer midaltitude regions where CCM2 overestimates surface solar fluxes relative to Pinker by as much as 100 W m−2. Most of the differences are associated with deficiencies in CCM2's prediction of cloud optical properties and cloud amount. However, significant differences also occur in clear-sky fluxes and surface albedo.