Meteorological effects on the evolution of high ozone episodes in the greater Seoul area.
Three high O3 episodes--7 days in 1992 (July 3-July 9), 9 days in 1994 (July 21-July 29), and another 3 days in 1994 (August 22-August 24)--were selected on the basis of morning (7:00 a.m.-10:00 a.m.) average wind direction and speed and daily maximum O3 concentrations in the greater Seoul, Korea, of 1990-1997. To better understand their characteristics and life cycles, surface data from the Seoul Weather Station (SWS) and surface and 850-hPa wind field data covering northeast Asia around the Korean Peninsula were used for the analysis. In the July 1992 episode, westerly winds were most frequent as a result of the influence of a high-pressure system west of the Korean Peninsula behind a trough. In contrast, in the July 1994 episode, easterly winds were most frequent as a result of the effect of a typhoon moving north from the south of Japan. Despite different prevailing wind directions, the peak O3 concentrations for each episode occurred when a sea/land breeze developed in association with weak synoptic forcing. The August 1994 episode, which was selected as being representative of calm conditions, was another typical example in which a well-developed
Global Environment Research Center, Korea Institute of Science and Technology, Seoul. ysghim@kist.re.kr
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D004784:Environmental Monitoring; D010083:Oxidants, Photochemical / Q000032:analysis* / Q000737:chemistry; D010126:Ozone / Q000032:analysis* / Q000737:chemistry; D011891:Rain; D012621:Seasons; D014919:Wind
D010083:Oxidants, Photochemical; D010126:Ozone