The Interannual Variation of Transboundary Contributions from Chinese Emissions of PM_(2.5) to South Korea

In recent years, several studies pointed out that anthropogenic emission sources in China which significantly contribute to the PM_(2.5) mass burden was an important cause of particulate pollution in South Korea. However, most studies generally focused upon a single pollution event. It is rare to see comprehensive research that captures those features prone to interannual variations concerning the transboundary pollutant contribution in South Korea using a unified method. In this paper, we establish the emission inventories covering East Asia in 2010, 2015, and 2017, and then conduct the source apportionment by applying a coupled regional air quality model called the Integrated Source Apportionment Module(ISAM). Comparison of simulated and observed PM_(2.5) mass concentration at 165 CNEMC(China National Environmental Monitoring Center) sites suggests that the PM_(2.5) concentrations are well represented by the modeling system. The model is used to quantitatively investigate the contribution from emission sources in China to PM_(2.5) concentrations over South Korea and those features found to be prone to interannual variations are then discussed. The results show that the average annual contribution of PM_(2.5) has dropped significantly from 28.0% in 2010 to 15.7% in 2017, which strongly suggests that China has achieved remarkable results in the treatment of atmospheric particulates.