Abstract
We estimated long-term foreign contributions to the particulate matter of 2.5 μm or less in diameter (PM2.5) concentrations in South Korea with a set of air quality simulations. The Weather Research and Forecasting (WRF)-Sparse Matrix Operator Kernel Emissions (SMOKE)-Community Multiscale Air Quality (CMAQ) modeling system was used to simulate the base and sensitivity case after a 50% reduction of foreign emissions. The effects of horizontal modeling grid resolutions (27- and 9-km) was also investigated. For this study, we chose PM2.5 in South Korea during 2010–2017 for the case study and emissions from China as a representative foreign source. The 9-km simulation results show that the 8-year average contribution of the Chinese emissions in 17 provinces ranged from 40–65%, which is ~4% lower than that from the 27-km simulation for the high-tier government segments (particularly prominent in coastal areas). However, for the same comparison for low-tier government segments (i.e., 250 prefectures), the 9-km simulation presented lowered the foreign contribution by up to 10% compared to that from the 27-km simulation. Based on our study results, we recommend using high-resolution modeling results for regional contribution analyses to develop an air quality action plan as the receptor coverage decreases.
Highlights
Many cities in South Korea often experience high particulate matter of 2.5 μm or less in diameter (PM2.5 ) levels that exceed the PM2.5 National Ambient Air Quality Standard [1]
Meteorological variations throughout modeling periods affect the air quality modeling results (subsequently modeled variations throughout modeling periods affect the air quality modeling results, we examined the Chinese contribution via long-term simulations modeled contribution estimates), we examined the Chinese contribution via long-term to account for variable weather conditions over multiple years
For the 250 prefectures, the contribution differences via the two simulations were consistent in many areas but at the same time, we observed that many prefectures with less than 50% Chinese contribution showed estimated contribution differences of up to 10% due to the modeling grid resolution (Figure 5c)
Summary
Many cities in South Korea often experience high particulate matter of 2.5 μm or less in diameter (PM2.5 ) levels that exceed the PM2.5 National Ambient Air Quality Standard [1]. It is necessary to perform air quality simulations with a fine-grid resolution to quantify the impact of local source impacts while a coarse-grid resolution is sufficient to estimate the contributions of the long-range transport of pollutants due to remote upwind sources such as Chinese emissions. For these reasons, a modeling approach needs to reconcile estimating the long-range transport of PM2.5 from Northeast Asian countries along with regional sources to understand the domestic and foreign contributions to the PM2.5 levels of specific regions as quantifying both of these contributions is crucial for pollution control policy-making.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
