Relationship between Western Pacific teleconnection pattern and aerosol concentrations over East Asia

The Western Pacific (WP) pattern is a primary mode of low-frequency variability over the North Pacific. The WP is characterized by a spatial anomaly distribution as a north-south dipole. We examine the relationship between WP index and aerosol concentrations over East Asia using the 3-D chemical transport model (GEOS-Chem) simulations for the period of 1980-2010. The model was driven by the MERRA assimilated meteorology with the emission estimates from the Streets et al. inventory. We used the fixed anthropogenic emissions for the whole periods to remove the effect of anthropogenic emissions changes on the model results. East Asia aerosol concentrations and WP index show that high and low aerosol concentrations years are respectively related to ENSO events such as La Niņa and El Niņo. In the strongest WP years, aerosol concentrations are relatively lower than ordinary years, whereas in the weakest WP years, aerosol concentrations are relatively high. High and low aerosols are associated with the wind and pressure fields over East Asia. This result implies that the meteorological variability is one of the important factors affecting the interannual variation of aerosol concentrations over East Asia.