Organic and elemental carbon in fine particles at Kosan, Korea

Concentrations of elemental carbon (EC) and organic carbon (OC) in fine particles at Kosan, Cheju Island Korea were observed during seven intensive measurement periods between 1994 and 1997. PM2.5 were collected on a pre-fired quartz filter by a low volume aerosol sampler and EC and OC concentrations were quantified by the selective thermal oxidation method with MnO2 catalyst. The OC concentrations were higher than those at other background areas in the world but the EC concentrations were lower than or comparable to those at other background areas in the world. The OC and EC concentrations varied depending on air parcel trajectories, higher concentrations were observed when air parcels were from southern China than those from northern China. Regional marine background levels of EC and OC were observed when air parcels were from the North Pacific. Except summer, the OC and EC concentrations show good relationship, implying both OC and EC had the same emission/transport characteristics outside of Cheju Island. Their relationships were poor during August 1994 and July 1995 when air parcels were from the North Pacific. It might be due to the biogenic emissions of OC around the site during summer.