Impact of Chemical Composition of Size-resolved Aerosol on Severe Haze in the National Park Area of Gyeongju, Korea

KYUNGWON KIM (1), Young J. Kim (2)

(1) Gyeongju University, (2) Gwangju Institute of Science and Technology

     Abstract Number: 1189
     Last modified: April 30, 2009

Abstract
The provision of beautiful landscape view at the national park improves an economic and a social phase of a nation. Severe haze, however, frequently occurred in the national park area of Gyeongju, Korea. In order to investigate the impact of chemical composition of size-resolved particles on visibility reduction, filter-based 2-hour (from 8 A.M. to 6 P.M.) and 14-hour (from 6 P.M. to 8 A.M.) size-resolved aerosol collections were carried out each sampling day at the visibility monitoring station of Gyeongju University in the national park area during the intensive monitoring period. Light attenuation coefficients were continuously measured using a transmissometer, a nephelometer, and an aethalometer. Aerosol chemical composition was reconstructed from elemental, ionic, and carbonaceous species using a proton induced X-ray emission, an ion chromatography, and a thermal optical transmittance method, respectively. Mass concentrations of PM$_(1.0), PM$_(2.5), and PM$_(10) increased to 38.2, 67.5, and 136.8 ug m$^(-3) under the severe haze below about 4 km. Sulfates particles was the largest contributor to light extinction under hazy condition. Organic matters accounted for about 26% of the average light extinction. However the average mass concentration of elemental carbon was extremely low during the intensive monitoring period. The geographic characteristic in the distance between Gyeongju and the peripheral mega-cities does only in tens km. The possibility of regional transport of visibility impairing aerosol with cause of severe haze in the national park area will not be able to exclude.