SEASONAL-VARIATION IN ATMOSPHERIC AEROSOLS CONCENTRATION COVERING NORTHERN KYUSHU, JAPAN AND SEOUL, KOREA

Atmospheric aerosols were collected from October 1990 to February 1992 in northern Kyushu (Tsushima and Ogori), Japan and Seoul, Korea, simu ltaneously using identical sampling system and chemical analysis metho ds. Observed data were analyzed with meteorological data to clarify th e seasonal variations in aerosol concentration and composition. Domina nt ion components of aerosol were SO42- in anion and NH4+ in cation. T he concentrations of ion components were higher in winter than those i n summer. Equivalent concentration ratio of particulate nitrate and su lfate (NO3-/SO42-) showed high value in Ogori having a peak in winter season. Equivalent concentration ratio of Ca2+ and sulfate (Ca2+/SO42- ) is highest in Seoul and shows no seasonal variation. On the contrary , Tsushima and Ogori showed low value in summer season. In summer, thi s area is affected by the atmospheric high-pressure system which devel oped at the southern Kyushu sea area and southerly monsoon wind predom inate. As the result of this, supply of Ca2+ from soil should be dimin ished in summer. Equivalent concentration ratio of particulate Cl- and Na+ (Cl-/Na+) in August was half compared with the ratio observed in February. Episode analysis of June 1991 and February 1992 indicated th e transportation of pollutants from the outside of Japan. Air masses f rom the Chinese continent have been concluded to bring the greatest am ount of anthropogenic pollutants to Korea and Japan. Copyright (C) 199 6 Elsevier Science Ltd