Simulation of future aerosol distribution, radiative forcing, and long-range transport in East Asia

Distributions of aerosol concentrations, optical properties, and wet deposition fluxes are simulated for the next fifty years using an aerosol transport model coupled with an atmospheric general circulation model. Treated species are sulfur dioxide, and all the main tropospheric aerosols, i.e., carbonaceous (black and organic carbons), sulfate, soil dust, and sea salt. We especially pay attention to distributions of anthropogenic carbonaceous aerosols, sulfate aerosols, and sulfur dioxide. The simulation uses the Special Report on Emissions Scenarios (SRES) of the Intergovernmental Panel on Climate Change (IPCC) as the future emission scenarios of anthropogenic pollutants. Simulated results suggest that carbonaceous aerosols continue to increase over industrial and densely populated regions for the next five decades, whereas sulfate aerosols decrease around Europe and North America. The aerosol single scattering albedo in the future is, therefore, calculated to become small gradually in the mid- and high-latitudes of the Northern Hemisphere. Sulfate aerosols and sulfur wet deposition fluxes are, on the other hand, simulated to increase only over East Asia. Black carbon and sulfate aerosols around Japan in 2050 are simulated to be two or three times as large as those in 2000 with one of the SRES scenarios. Hence this suggests that pollutants originating from the East Asian continent can seriously affect the atmospheric quality in Japan in the next several decades.