The Influence of Anthropogenic Aerosols On the Arctic Sea Ice

Atmospheric aerosols from natural or anthropogenic sources have profound impacts on the regional and global climate. Currently the radiative forcing of aerosols predicted by global climate models remains highly uncertain, representing the largest uncertainty in climate predictions. Over the Arctic, sea ice cover is found to be shrinking dramatically, but the role of anthropogenic aerosols transported from lower latitudes remains elusive. Using a state-of-the-art fully coupled climate model (NCAR/DOE CESM1.0.4), we quantify the equilibrium response of the Arctic sea ice to various aerosol and greenhouse-gas forcings. The influence of disparate evolutions of anthropogenic aerosol loading in developed and developing countries since 1970s is assessed individually. Under different forcing scenarios, we find that the annual mean sea ice changes are closely related with perturbations in surface radiation fluxes on the regional scale, but the ratio between those two depends on the radiation forcing strength. The future changes of the Arctic sea ice due to projected evolutions of anthropogenic aerosols in the Representative Concentration Pathways will be reported.