Keywords:PM2.5, CAMx, PAST
PM2.5 has recently been adopted as the national ambient air quality standard (NAAQS) as of 2015 in Korea, so official measurement began in 2015. The annual average concentration of PM2.5 in Busan was 26 μg/m3 in 2015, 27 in 2016, and showed an increasing trend of exceeding NAAQS (below 25 μg/m3). Korea is located below China, so pollutants emitted from the eastern region of China have also been identified as having a significant impact. In this study, a three-dimensional, numerical air quality model, the Comprehensive Air Quality Model with Extensions (CAMx), was coupled with Particulate Matter Source Apportionment Technology (PSAT) to analyze region and source category contributions to PM2.5 content and related chemical components. This research took place in Busan, Korea, during May 2017. Emission-based models require both meteorological information and emission data. Four nested modeling domains were constructed for both the meteorological model and the chemical transport model (CTM) in this study. Grid resolutions were 27 km, 9 km, 3 km and 1km, respectively, and the corresponding nesting grids are denoted as domain1, domain2, domain3 and domain4. Meteorological input data was determined with a WRF meteorological model using National Centers for Environmental Prediction (NCEP) Final (FNL) global analysis data. The Clean Air Policy Support System (CAPSS) developed by the Ministry of Environment was used to gather air pollutant emission data within South Korea. For other areas, the Model Inter-Comparison Study for Asia (MEIC) and Regional Emission Inventory in Asia (REAS) were used to input air pollutant emission data. According to the CAMx results, the soil-derived component represented the highest proportion. The second highest was sulfate (23.6%), followed by nitrate (12.7%) and ammonium (12.4%). The regional contribution caused by emission sources in Busan represented 36.9% of PM2.5 content. However, the contribution rate from China was 34.1%, similar to that of Busan.
This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(2017R1D1A3B03036152)