Numerical simulation of interannual variation in transboundary contributions from Chinese emissions to PM2.5 mass burden in South Korea

Abstract

In recent years, extensive air pollution control measures have been adopted in China. Several studies have shown that the air quality has improved significantly in central and eastern parts of China since 2013. The transport contributions from emission sources in China to the PM2.5 mass burden in South Korea is therefore likely to change under the background of an emission flux decline. In this study, anthropogenic and natural emission data for East Asia were collected and emission inventories were constructed for 2010, 2015, and 2017. A numerical source apportionment was conducted using the Integrated Source Apportionment Method (ISAM) coupled with the Regional Atmospheric Modeling System - Community Multiscale Air Quality (RAMS-CMAQ) regional air quality model to simulate the pollutant transport features of emission sources in China. The contribution to the PM2.5 mass burden in South Korea was obtained quantitatively and its interannual variability was assessed. The results showed that the PM2.5 concentration decreased annually, especially in the seriously polluted regions, including North China, Central China, Yangtze River Delta, middle reaches of the Yangtze River, Sichuan Basin, and Pearl River Delta. The proportional contribution was higher in winter and lower in summer, which was largely due to the seasonal variation in the prevailing wind direction. In addition, the annual average contribution to the PM2.5 mass burden in South Korea dropped significantly from 28.0% in 2010 to 15.7% in 2017, which further proved that the management of atmospheric particulate pollution in China has been effective.