model description and evaluation

Abstract. Anthropogenic aerosol effects on climate pro-duce one of the largest uncertainties in estimates of radia-tive forcing of past and future climate change. Much of this uncertainty arises from the multi-scale nature of the in-teractions between aerosols, clouds and large-scale dynam-ics, which are difficult to represent in conventional general circulation models (GCMs). In this study, we develop a multi-scale aerosol-climate model that treats aerosols and clouds across different scales, and evaluate the model perfor-mance, with a focus on aerosol treatment. This new model is an extension of a multi-scale modeling framework (MMF) model that embeds a cloud-resolving model (CRM) within each grid column of a GCM. In this extension, the effects of clouds on aerosols are treated by using an explicit-cloud parameterized-pollutant (ECPP) approach that links aeroso