Evaluations of Surface Shortwave and Longwave Radiation from Earth System Models of CMIP5

Abstract:

Surface shortwave radiation (R_s) and longwave radiation (L_d) are the key components of energy budget in the climate system. Studies have shown that the biases of simulated clouds display significant spatial pattern, which may introduce an important spatial pattern of the biases of simulated R_s and L_d. Therefore the evaluation results of global climate model R_s and L_d simulations may depend on the location of the ground observations. In this study, comprehensive ground-based observations were used to evaluate the R_s and L_d simulations from Earth System Models (ESMs) in the Coupled Model Intercomparison Project Phase 5 (CMIP5). We found that the overestimation of R_s and the underestimation of L_d still exist in CMIP5. We also quantified the representation of ground-based observations and their uncertainties in the global estimations of R_s and L_d. After removing the biases of CMIP5 ESMs, the globally averaged R_s is estimated to be 187 W m^-2 from 2000 to 2005, and the globally averaged L_d from 1992 to 2005 is estimated to be 341 W m^-2.