Strong impact of Northern Hemisphere Atmospheric Circulation on Inter-annual Variability of PM10 Concentration in South Korea during winter season

In recent years, there has been a growing interest in fine dust particles in South Korea due to frequent serious air pollution episodes. Particulate matter with a diameter <10μm (PM₁₀) concentration is affected by emissions, deposition, atmospheric stability, and ventilation effects, but the effects of large-scale atmospheric circulation in the Northern Hemisphere on the PM₁₀ concentration in Korea are not well known. In this study, using the monthly mean PM₁₀ concentration data of 71 monitoring stations in South Korea provided by the Korea National Institute of Environmental Research for the period 2001-2016 and the data of the National Centers for Environmental Prediction-National Center for Atmospheric Research Reanalysis data for 1979-2016, the characteristics of the Northern Hemisphere atmospheric circulation affecting inter-annual variability of PM₁₀ concentration in winter were analyzed. PM₁₀ concentration in Korea during winter was largely influenced by near-surface wind speed index than potential air temperature gradient index in various ventilation effects, and pollution potential index defined as a linear combination of the two ventilation indexes could explain major inter-annual variability. In particular, the inter-annual variability of the PM₁₀ concentration in Korea was significantly affected by the intensity of the Ural blocking and north-south movement of the Jet stream caused by the Rossby wave propagating from the Arctic and the North Atlantic, implying that climate change by greenhouse gases can be a strong potential factor for the high concentration of PM₁₀ in Korea. We also discussed the major difference in atmospheric circulation that affects inter-annual variability of PM₁₀ concentrations in the East China Plains region and Korea.