Studying Aerosol-Cloud-Climate Interactions over East Asia Using WRF/Chem

East Asia provides an ideal testbed to study aerosol feedbacks into climate via direct and indirect effects because of high anthropogenic emissions and unique climatology. In this work, an online coupled meteorology-chemistry model, WRF/Chem, is applied to simulate air quality and climate interactions for multiple months in 2001, 2005, and 2008 to characterize long-term seasonal variations of pollutant concentrations and quantify the contributions of anthropogenic aerosols to aerosol direct and indirect effects. The results show a reasonably good performance for most meteorological variables and chemical species concentrations. Large biases in some variables may be caused by large uncertainties in emissions. Anthropogenic aerosols in East Asia can reduce the surface net solar radiation by up to 6 % and enhance cloud condensation nuclei and cloud droplet number concentrations by a factor of up to 3 on domain-average, with much greater impacts over urban areas. These results suggest that aerosol feedbacks are potentially important over polluted areas and should be taken into account in the development of emission control and climate mitigation policies for areas where the aerosol feedback signals are strong.