• Title/Summary/Keyword: Atmospheric $SO_2$

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Analysis Study of Air Pollutants at Kosan, Cheju Island (제주도 고산에서의 대기오염물질 측정 및 분석에 관한 연구)

  • 홍민선;이상훈;이동섭;강창희;박경윤
    • Journal of Korean Society for Atmospheric Environment
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    • v.8 no.4
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    • pp.257-261
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    • 1992

  • Measurements of sulfur dioxide, ozone and meteorological parameters at Kosan, Cheju Island show clear indications of the influence of the source areas of both Korean Peninsular and Mainland China. Monthly mean levels in February of $SO_2$ and $O_3$ were 1.4 and 44 ppb, respectively. These Values are 2-30 times higher than those measured in remote are as such as Bermuda Island and Uto Island in Finland. Ozone loss in February and March were found to be 0.2 and 0.36 ppb/hr and correlation coefficient between ozone and solar radiation was 0.48. Also it was found that $SO_2$ levels were more than 2 times higher when the prevailing winds from WSW-NNE than from the rest.

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Size Distribution Characteristics of Particulate Mass and Ion Components at Gosan, Korea from 2002 to 2003

  • Han J.S.;Moon K.J.;Lee S.J.;Kim J.E.;Kim Y.J.
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.E1
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    • pp.23-35
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    • 2005

  • Size distribution of particulate water-soluble ion components was measured at Gosan, Korea using a micro-orifice uniform deposit impactor (MOUDI). Sulfate, ammonium, and nitrate showed peaks in three size ranges; Sulfate and ammonium were of dominant species measured in the fine mode ($D_{p} < 1.8 {\mu}m$). One peak was observed in the condensation mode ($0.218\sim0.532{\mu}m$), and the other peak was obtained in the droplet mode ($0.532\sim1.8{\mu}m$). Considering the fact that the equivalent ratios of ammonium to sulfate ranged from 0.5 to 1.0 in these size ranges, it is inferred that they formed sufficiently neutralized compounds such as ($NH_{4})_{2}SO_{4} and (NH_{4})_{3}H(SO_{4})_{2}$ during the long-range transport of anthropogenic pollutants. On the other hand, nitrate was distributed mainly in the coarse mode ($3.1\sim6.2{\mu}m$) combined with soil and sea salt. Two sets of MOUDI samples were collected in each season. One sample was collected when the concentrations of criteria air pollutants were relatively high, but the other represented relatively clean air quality. The concentrations of sulfate and ammonium particles in droplet mode were the highest in winter and the lowest in summer. When the air quality was bad, the increase of nitrate was observed in the condensation mode ($0.218\sim0.282{\mu}m$). It thus suggests that the nitrate particles were produced through gas phase reaction of nitric acid with ammonia. Chloride depletion was remarkably high in summer due to the high temperature and relative humidity.

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A Time Series Analysis for the Monthly Variation of $SO_2$ in the Certain Areas (ARIMA model에 의한 서울시 일부지역 $SO_2$ 오염도의 월변화에 대한 시계열분석)

  • Kim, Kwang-Jin;Lee, Sang-Hun;Chung, Yong
    • Journal of Korean Society for Atmospheric Environment
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    • v.4 no.2
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    • pp.72-81
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    • 1988

  • The typical ARIMA model which was developed by Box and Jenkins, was applied to the monthly $SO_2$ data collected at Seoungsoo and Oryudong in metropolitan area over five years, 1982 to 1986. To find out the changing pattern of $SO_2$ concentration, autocorrelation and partial autocorrelation analysis were undertaken. The three steps of time series model building were followed and the residual series was found to be a random white noise. The results of this study is summarized as follows. 1) The monthly $SO_2$ series was found to be a non-stationary series which which has a periodicity of 12 months. After eliminating the periodicity by differencing, the monthly $SO_2$ series became a stationary series. 2) The ARIMA seasonal model of the $SO_2$ was determined to be ARIMA $(1, 0, 0)(0, 1, 0,)_{12}$ model. 3) The model equations based on the prediction were: for Seoungsoodong: $Y_t = 0.5214Y_{t-1} + Y_{t-12} - 0.5214Y_{t-13} + a_t$ for Oryudong: $Y_t = 0.8549Y_{t-1} + Y_{t-12} - 0.8549Y_{t-13} + a_t$ 4) The validity of the model identified was checked by compairing the measured $SO_2$ values and one-month-ahead predicted values. The result of correlation and regression analysis is as follows. Seoungsoodong: $Y = 0.8710X + 0.0062 r = 0.8768$ Oryudong : $Y = 0.8758X + 0.0073 r = 0.9512$

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