강원도 춘천에서 측정한 PM 2.5 의 탄소 및 이온성분 농도 특성 및 고농도 사례 분석

Anthropogenic emissions of PM 2.5 in Chuncheon are considered to be low according to the national emissions inventory; however, the atmospheric PM 2.5 concentrations have been reported to be higher than or at least similar to those measured in metropolitan (e.g. Seoul) and/or in industrial cities (e.g. Incheon, Ulsan). In this study, the concentrations of PM 2.5 and its ionic and carbonaceous compounds were measured from Jan. 2013 to Dec. 2014 in Chuncheon, Korea to identify the characteristics of high PM 2.5 concentration event. Average PM 2.5 concentration was 34.6 μg/㎥, exceeding the annual air quality standard (25 μg/㎥). The most abundant compound was organic carbon (OC), comprising 26% of PM 2.5 mass, followed by SO₄ 2- . Among 14 high concentration events, three events showed clearly enhanced contributions of OC, SO₄ 2- , NO₃ - and NH₄ + to PM 2.5 under the fog events. One event observed in summer showed high concentration of SO42- while the high wind speeds and the low PM2.5/PM 10 ratios were observed for the two high concentration events. These results indicate that the secondary aerosol formation under the fog events and high atmospheric temperature as well as the regional and/or the long-range transport were important on enhancing PM 2.5 concentration in Chuncheon. Cluster analysis based on back trajectories also suggested the significant impacts of regional transport from China and metropolitan areas of Korea on PM 2.5 in Chuncheon.