We analyzed the recent characteristics of Particulate Matter (PM) including PM10 (PM with diameter of less than 10μm) and PM2.5 (PM with diameter of less than 2.5μm) observed in Busan metropolitan area, and compared them with those measured in Seoul metropolitan area. This analysis includes the monthly, seasonal, and annual variations and differences, in emissions and chemical compositions observed in both Busan and Seoul areas. Synoptic meteorological conditions were investigated at the time when high PM concentrations occurred in each of the two areas. The results showed clearly decreasing trends of annual mean concentrations with strong seasonal variations: lower in summer and higher in winter in both areas. In comparison with Seoul, the seasonal variation in Busan demonstrated relatively lower, but showed greater summer fluctuations than in Seoul metropolitan area. This is implying the importance of secondary generation of PM in summer via active photochemical reaction in Busan area. In high concentration days, Busan’s chemical composition of sulfate was higher than that of nitrate in summer, whereas nitrate was higher than sulfate in Seoul. The ratios of NO3 - to SO4 2-(N/S ratio) showed lower in Busan approximately by a factor of 1/2(half of N/S ratio) in Busan compared with that in Seoul. Others such as synoptic characteristics and emission differences were also discussed in this study.

Abstract
1. 서 론
2. 연구방법
    2.1. 측정망 자료 및 배출량
    2.2. 고농도 사례 선정
3. 결과 및 분석
    3.1. 미세먼지 농도 특성 분석
    3.2. 미세먼지 화학성분 특성
    3.3. 고농도 사례 분석 – 종관 일기도 및 대기화학 특성
4. 요약 및 결론
REFERENCES

• 김종민(부산대학교 지구환경시스템학부) | Jong-Min Kim (Atmospheric Sciences Major, Department of Earth Environmental System, Pusan National University)
• 조유진(부산대학교 지구환경시스템학부) | Yu-Jin Jo (Atmospheric Sciences Major, Department of Earth Environmental System, Pusan National University)
• 양금희(부산대학교 지구환경시스템학부) | Geum-Hee Yang (Atmospheric Sciences Major, Department of Earth Environmental System, Pusan National University)
• 허국영(환경부 국가미세먼지정보센터 정책지원팀) | Gookyoung Heo (Policy Support Team, National Center for Fine Dust Information)
• 김철희(부산대학교 지구환경시스템학부) | Cheol-Hee Kim (Atmospheric Sciences Major, Department of Earth Environmental System, Pusan National University) Corresponding author