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.

中文翻译：

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西非观测和CMIP5模拟的辐射通量变异性

我们在耦合模型比对项目（CMIP5）中探索了一般环流模型的能力，以重建西非大气层顶部和地面辐射通量的观测季节变化。这测试了CMIP5模型描述辐射能分配的能力，这是我们了解当前气候及其未来变化的基础。我们使用15年的月度云和地球辐射能系统能量平衡和填充（EBAF）产品，以及其他卫星，再分析和地面站产品。我们发现CMIP5多模型平均值通常在参考产品范围内，年平均CMIP5多模型平均值–大气反射顶部短波辐射的EBAF为-0.5 W m ^-2，而4.6 W m ^-2在西非的长波辐射中。但是，模型季节周期的年平均值范围较大（37.2和34.0 W m ^-2分别用于反射短波辐射和长波辐射）。我们在全天通量中使用季节和区域对比来推断数值模型中西非季风的表示会影响辐射能的分配。与过去的研究一致，使用晴空表面通量，我们发现这些模型倾向于比EBAF具有更多的向下波短波辐射和更少的向下波长波辐射。我们发现较干燥且气溶胶负荷较低的模型往往显示出最大的差异。我们发现有证据表明，与EBAF中的水蒸气相比，气溶胶变异性对下行流短波辐射的调制作用更大，而在大多数CMIP5模型中则观察到相反的作用。