摘要：We explore the ability of general circulation models in the Coupled Model Intercomparison Project (CMIP5) to recreate observed seasonal variability in top‐of‐the‐atmosphere and surface radiation fluxes over West Africa. This tests CMIP5 models' ability to describe the radiative energy partitioning, which is fundamental to our understanding of the current climate and its future changes. We use 15 years of the monthly Clouds and the Earth's Radiant Energy System Energy Balanced and Filled (EBAF) product, alongside other satellite, reanalysis, and surface station products. We find that the CMIP5 multimodel mean is generally within the reference product range, with annual mean CMIP5 multimodel mean—EBAF of −0.5 W m −2 for top‐of‐the‐atmosphere reflected shortwave radiation, and 4.6 W m −2 in outgoing longwave radiation over West Africa. However, the range in annual mean of the model seasonal cycles is large (37.2 and 34.0 W m −2 for reflected shortwave radiation and outgoing longwave radiation, respectively). We use seasonal and regional contrasts in all‐sky fluxes to infer that the representation of the West African monsoon in numerical models affects radiative energy partitioning. Using clear‐sky surface fluxes, we find that the models tend to have more downwelling shortwave and less downwelling longwave radiation than EBAF, consistent with past research. We find models that are drier and have lower aerosol loading tend to show the largest differences. We find evidence that aerosol variability has a larger effect in modulating downwelling shortwave radiation than water vapor in EBAF, while the opposite effect is seen in the majority of CMIP5 models. Plain Language Abstract The balance of incoming solar, or shortwave, radiation and longwave radiation emitted from the Earth's surface and atmosphere, is a fundamental variable of our climate system. It is therefore important for climate models to be able to reproduce the variability in radiative fluxes in order to have confidence in our ability to describe future climate, especially for vulnerable regions such as West Africa. In this study, we use 15 years of data from satellite instruments and surface stations to test how well climate models simulate observed variations in radiation over West Africa. We find that although the mean model behavior is similar to the observations (within 0.5 W m −2 , or 1%, for annual mean shortwave radiation, 4.6 W m −2 , or 2%, for longwave radiation), there is a large range model values. We link model‐observation differences to the progression of the West African monsoon, atmospheric water vapor, and aerosol. Concentrating on radiation reaching the surface under cloud‐free conditions, we find that models which are drier and have less aerosol have the largest differences in longwave radiation, and the relative impact of aerosols and water vapor on shortwave radiation differs between our reference and the models.
