Estimation of winter PM2.5 concentrations in East Asia associated with climate variability

Interannual variability in large circulations associated with climate connections, such as monsoon and El Niño, have a significant impact on winter PM_2.5 concentrations in East Asia. In this study, we use the global 3D chemical transport model (GEOS-Chem) over the last 35 years to investigate the relationship between major climate variability and winter PM_2.5 concentrations in East Asia. First, the model is evaluated by comparing the simulated and observed aerosol concentrations with the ground and satellite-based aerosol concentrations. The results indicate that this model well reproduces the variability and magnitude of aerosol concentrations observed in East Asia. Sensitivity simulations are then used with fixed anthropogenic emissions to investigate the effects of meteorological variability on changes in aerosol concentrations in East Asia. The variability of winter PM_2.5 concentrations in northern East Asia was found to be closely correlated with ENSO and Siberian high position. To predict PM_2.5 concentrations using key climate indices, we develop multiple linear regression models. As a result, the predicted winter PM_2.5 concentrations using the key climate index are well reproduced in the simulated PM_2.5 concentrations, especially in northern East Asia.