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Abstract

The radiative forcing of greenhouse gases and aerosols has characteristic distribution patterns, which influence global and regional energy budgets and lead to profound climate responses. Because of the multivariable-function nature of radiative transfer, the forcing distribution is controlled by forcing agents, as well as environmental variables. In this work, we aim to 1) determine the pattern of the radiative forcing of greenhouse gases and aerosols based on accurate radiative transfer computations, and 2) to quantify the effects of both forcing agents and environmental factors on the distribution pattern based on analytical equations determined from statistical analysis. We find that the majority of the temporospatial variance of the greenhouse gas and aerosol forcing can be well explained by multivariate regression models. Based on the radiative sensitivities quantified from this approach, we then assess how the changes in the respective controlling factors lead to the changes, as well as the inter-climate model differences, in the forcing magnitude and distribution. A few interesting and important environmental effects are identified. For example, the change in surface albedo is found to strongly influence the trend in the regional aerosol forcing in the Arctic, as well as the meridional energy transport in this region.