资源环境科技发展态势分析平台

We use the best currently available in situ and satellite-derived surface and top-of-the-atmosphere (TOA) shortwave radiation observations to explore climatological annual cycles of fractional (i.e., normalized by incoming radiation at the TOA) atmospheric shortwave absorption a similar to on a global scale. The analysis reveals that a similar to is a rather regional feature where the reported nonexisting a similar to in Europe is an exception rather than the rule. In several regions, large and distinctively different a similar to are apparent. The magnitudes of a similar to reach values up to 10% in some regions, which is substantial given that the long-term global mean atmospheric shortwave absorption is roughly 23%. Water vapor and aerosols are identified as major drivers for a similar to while clouds seem to play only a minor role for a similar to. Regions with large annual cycles in aerosol emissions from biomass burning also show the largest a similar to. As biomass burning is generally related to human activities, a similar to is likely also anthropogenically intensified or forced in the respective regions. We also test if climate models are able to simulate the observed pattern of a similar to. In regions where a similar to is driven by the annual cycle of natural aerosols or water vapor, the models perform well. In regions with large a similar to induced by biomass-burning aerosols, the models' performance is very limited.