Inter-model Diversity in Aerosol Sensitive Regions

Abstract:

Anthropogenic aerosol can have a pronounced influence on regional climate change, and has been shown to be important in many regional processes, including the Asian and West African monsoons. Using a subset of CMIP5 models that provide anthropogenic aerosol only experiments, we identify several regions where there is a correlation between water cycle changes in historical all forcing experiments, and those in experiments forced only by changes in anthropogenic aerosol. Analysis of shortwave and latent heat fluxes identifies regions that are collocated with the major aerosol emission regions, and areas with persistent stratocumulus coverage. However, analysis of near-surface temperature suggests that areas without local aerosol perturbations may also be sensitive to anthropogenic aerosol forcing.

We quantify the role of aerosol in climate change in these regions for a larger set of CMIP5 models. In regions where aerosol is shown to have a strong influence on regional climate, we quantify the inter-model diversity in both the aerosol perturbation, and the climate response, and suggest physical mechanisms for the differences.