• Title/Summary/Keyword: Atmospheric Dispersion

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Application and First Evaluation of the Operational RAMS Model for the Dispersion Forecast of Hazardous Chemicals - Validation of the Operational Wind Field Generation System in CARIS (유해화학물질 대기확산 예측을 위한 RAMS 기상모델의 적용 및 평가 - CARIS의 바람장 모델 검증)

  • Kim, C.H.;Na, J.G.;Park, C.J.;Park, J.H.;Im, C.S.;Yoon, E.;Kim, M.S.;Park, C.H.;Kim, Y.J.
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.5
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    • pp.595-610
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    • 2003

  • The statistical indexes such as RMSE (Root Mean Square Error), Mean Bias error, and IOA (Index of agreement) are used to evaluate 3 Dimensional wind and temperature fields predicted by operational meteorological model RAMS (Regional Atmospheric Meteorological System) implemented in CARIS (Chemical Accident Response Information System) for the dispersion forecast of hazardous chemicals in case of the chemical accidents in Korea. The operational atmospheric model, RAMS in CARIS are designed to use GDAPS, GTS, and AWS meteorological data obtained from KMA (Korean Meteorological Administration) for the generation of 3-dimensional initial meteorological fields. The predicted meteorological variables such as wind speed, wind direction, temperature, and precipitation amount, during 19 ∼ 23, August 2002, are extracted at the nearest grid point to the meteorological monitoring sites, and validated against the observations located over the Korean peninsula. The results show that Mean bias and Root Mean Square Error are 0.9 (m/s), 1.85 (m/s) for wind speed at 10 m above the ground, respectively, and 1.45 ($^{\circ}C$), 2.82 ($^{\circ}C$) for surface temperature. Of particular interest is the distribution of forecasting error predicted by RAMS with respect to the altitude; relatively smaller error is found in the near-surface atmosphere for wind and temperature fields, while it grows larger as the altitude increases. Overall, some of the overpredictions in comparisons with the observations are detected for wind and temperature fields, whereas relatively small errors are found in the near-surface atmosphere. This discrepancies are partly attributed to the oversimplified spacing of soil, soil contents and initial temperature fields, suggesting some improvement could probably be gained if the sub-grid scale nature of moisture and temperature fields was taken into account. However, IOA values for the wind field (0.62) as well as temperature field (0.78) is greater than the 'good' value criteria (> 0.5) implied by other studies. The good value of IOA along with relatively small wind field error in the near surface atmosphere implies that, on the basis of current meteorological data for initial fields, RAMS has good potentials to be used as a operational meteorological model in predicting the urban or local scale 3-dimensional wind fields for the dispersion forecast in association with hazardous chemical releases in Korea.

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Simulations of Pollutant Dispersion over Rectangular Building (사각 건물 주위의 오염물 확산에 대한 수치해석적 연구)

  • Hong B. Y.;Park C. G.
    • Journal of computational fluids engineering
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    • v.6 no.4
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    • pp.1-7
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    • 2001

  • Wind flow perturbations, recirculations and turbulence generated by buildings often dominate air pollutant distributions around buildings. This paper describes dispersion of contaminants in the vicinity of a building by solving the concentration equation based on previously simulated wind flow field. Turbulence closure is achieved by using the standard k-ε two-equation model. The paper shows application of the CIP method for solving a species concentration equation of contaminant gas around a rectangular building for two different sources under conditions of neutral atmospheric stratification. Results have been compared to the experimental data and the previous numerical results by hybrid scheme. The computational results of concentration profiles by the CIP method agree well with experimental data.

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Numerical Simulations of Using CIP Method for Dispersion of Pollutants around a Building (CIP 방법을 이용한 건물 주위의 오염물 확산에 대한 수치해석)

  • Hong, Bo-Young;Park, Chan-Guk
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.723-728
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    • 2001

  • Wind flow perturbations, recirculations and turbulence generated by buildings often dominate air pollutant distributions around buildings. This paper describes dispersion of contaminants in the vicinity of a building by solving the concentration equation based on previously simulated wind flow field. Turbulence closure is achieved by using the standard k-e two-equation model. The paper shows application of the CIP method for solving a species concentration equation of contaminant gas around a rectangular building for two different sources under conditions of neutral atmospheric stratification. Results have been compared to the experimental data and the previous numerical results by hybrid scheme. The computational results of concentration profiles by the CIP method agree well with experimental data.

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Atmospheric Environment Prediction to Consider SST and Vegetation Effect in Coastal Urban Region (해수면온도와 식생효과를 고려한 연안도시지역의 대기환경예측)

  • Ji, Hyo-Eun;Lee, Hwa-Woon;Won, Gyeong-Mee
    • Journal of Environmental Science International
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    • v.18 no.4
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    • pp.375-388
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    • 2009

  • Numerical simulation is essential to indicate the flow of the atmosphere in the region with a complicated topography which consists of many mountains in the inland while it is neighboring the seashore. Such complicated topography produces land and sea breeze as the mesoscale phenomenon of meteorology which results from the effect of the sea and inland. In the mesoscale simulation examines, the change of the temperature in relation to the one of the sea surface for the boundary condition and, in the inland, the interaction between the atmosphere and land surface reflecting the characteristic of the land surface. This research developed and simulated PNULSM to reflect both the SST and vegetation effect as a bottom boundary for detailed meteorological numerical simulation in coastal urban area. The result from four experiments performed according to this protocol revealed the change of temperature field and wind field depending on each effect. Therefore, the lower level of establishment of bottom boundary suitable for the characteristic of the region is necessary to figure out the atmospheric flow more precisely, and if the characteristic of the surface is improved to more realistic conditions, it will facilitate the simulation of regional environment.

  • https://doi.org/10.5322/JES.2009.18.4.375 인용 PDF KSCI