A comparison of meteorology-driven interannual variations of surface aerosol concentrations in the Eastern United States, Eastern China, and Europe

Abstract

By the GEOS-Chem simulation with fixed anthropogenic and biomass burning emissions, this study exhibits the differences in interannual variations (IAVs) of surface-layer PM2.5 concentrations among three populated regions, the eastern United States (US), eastern China, and Europe driven by variations in meteorological parameters. In the eastern US, PM2.5 concentrations have relatively small IAVs with no explicit seasonality, with the absolute percent departure from the mean (APDM) values of 4-16% in four seasons. The IAVs of PM2.5 are found to be large in North China and the northwestern Europe during winter and spring. The APDM values are 24-28% in winter and 32-36% in spring in eastern China, and 32-36% in winter and 20-24% in spring in Europe. Additionally, we obtain the key meteorological parameters that drive the IAVs of PM2.5 by the stepwise multiline regression model (SLR) containing 8 meteorological variables. The most important meteorological variables over the eastern US, eastern China, and Europe are, respectively, the westerly at 850 hPa, surface wind speed, and the planetary boundary layer height in winter, and precipitation, relative humidity, and surface temperature in summer.