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Park S.-M.,National Institute of Environmental Research Kyungseo dong | Park S.-M.,Hankuk University of foreign Studies | Kim J.-S.,Transportation Institute | Lee G.,Hankuk University of foreign Studies | And 4 more authors.
Asian Journal of Atmospheric Environment | Year: 2015

We measured the concentrations of five aromatic hydrocarbons (benzene, toluene, ethylbenzene, m,pxylene, and styrene) in the atmosphere during four seasonal campaigns at Deokjeok and Jeju Islands in the Yellow Sea from October 2005 to June 2006. Toluene was the most abundant aromatic hydrocarbon, with median of 0.24 ppb at Deokjeok and 0.20 ppb at Jeju, followed by benzene (0.21 ppb, 0.15 ppb) and m,p-xylene (0.06 ppb, 0.06 ppb). Aromatic hydrocarbon measurements exhibited the typical seasonality of the major emission sources, such as vehicle exhaust, solvent evaporation, and regional circulation patterns. The ratios of m,p-xylene/ethylbenzene of 1.57 at Deokjeok and 1.05 at Jeju reflected the degree of proximity to outflows of each source region, South Korea and China. The toluene/benzene ratios of 1.0 were consistently both on field observations and on the 3-D chemical model simulation, which is slightly higher than that in the Western Pacific area. It implied that the air over the Yellow Sea was influenced to a great extent by the surrounding areas. We confirmed that current emission inventories of aromatic hydrocarbons in Northeast Asia reasonably reproduced temporal and spatial variations of toluene and benzene over the Yellow Sea. Source

Kim S.-Y.,National Institute of Environmental Research Kyungseo dong | Seo S.-J.,National Institute of Environmental Research Kyungseo dong | Park H.-J.,National Institute of Environmental Research Kyungseo dong | Son J.-S.,National Institute of Environmental Research Kyungseo dong | And 2 more authors.
Asian Journal of Atmospheric Environment | Year: 2013

The purpose of this study is to understand distributional characteristics in the atmospheric concentrations of O3 and its precursors based on data taken at the southern Korean coast. The average O3 concentration in the high altitude was found to range from 32.3 to 90.8 ppb with a maximum concentration of 132 ppb. The ambient O3 concentration was high at altitudes of 1000 m and 500 m above the southern sea near Gwangyang Bay and an industrial area containing emission sources. The daily mean concentrations of NOy and CO were 6.7-24.2 ppb and 0.152-0.487 ppm, respectively. During the aerial measurement period, the highest mean concentration of O3 was observed on June 1. The aerial measurement results showed that the maximum ozone concentration was observed to be 132 ppb in the high altitude the southernmost part of Yeosu. The measurement of vertical wind fields in the air indicated that O3 formed in the southernmost part of Yeosu was transported by strong southwesterly winds to the northeast of Gwangyang Bay. This led to a ground O3 concentration of over 100 ppb in Jinju, the northeastern part of Gwangyang Bay. On August 9, when the maximum O3 concentration was 50 ppb, the measurement results showed that O3 concentrations were relatively low compared to other days. In particular, low NO2 and TVOC concentrations were observed, both of which serve to form O3 in photochemical reactions. Source

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