Seasonal Characteristics of PM2.5 Water Content at Seoul and Gosan, Korea

서울과 고산의 PM2.5 수분함량 계절 특성

  • Lee, Hyung-Min (Department of Environmental Science and Engineering, Ewha Womans University) ;
  • Kim, Yong-Pyo (Department of Environmental Science and Engineering, Ewha Womans University)
  • 이형민 (이화여자대학교 환경공학과) ;
  • 김용표 (이화여자대학교 환경공학과)
  • Published : 2010.02.28


Water content of $PM_{2.5}$ (particles in the atmosphere with a diameter of less than or equal to a nominal $2.5{\mu}m$) was estimated by using a gas/aerosol equilibrium model, SCAPE2, for the particles collected at Seoul and Gosan, Korea. From measured and analyzed characteristics of the particles, the largest difference between Seoul and Gosan is the proportions of total ammonia (t-$NH_3$=gas phase $NH_3$+particle phase ${NH_4}^+$), total nitric acid (t-$HNO_3$=gas phase $HNO_3$+particle phase ${NO_3}^-$) and sulfuric acid ($H_2SO_4$). Even though both sites have sufficient t-$NH_3$ to neutralize acidic species such as $H_2SO_4$, t-$HNO_3$, and t-HCl (total chloric acid=gas phase HCl+particle phase $Cl^-$), equivalent fraction of t-$NH_3$ and t-$HNO_3$ are higher at Seoul and $H_2SO_4$ is higher at Gosan. Based on the modeling result, it is identified that the $PM_{2.5}$ at Seoul is more hygroscopic than Gosan if the meteorological conditions are the same. To reduce water content of $PM_{2.5}$, and thus, mass concentration, control measures for ammonia and nitrate reduction are needed for Seoul, and inter-governmental cooperation is required for Gosan.


Gas-particle equilibrium model;$PM_{2.5}$ water content;Inorganic fraction;Ammonia richness


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