• Title/Summary/Keyword: Air dispersion model

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An Analysis of the Case related with High PM10 Concentrations Using a Fine Grid Air Dispersion Modeling in Ansan Area (미세 격자 대기 확산 모델링을 통한 안산지역 PM10 고농도 사례 분석)

  • 송동웅;송창근
    • Journal of Environmental Science International
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    • v.12 no.9
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    • pp.977-986
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    • 2003
  • In this study, the scenario for a numerical modeling of the fine grid scale air dispersion phenomena was proposed and an analysis of the special event which was occurred on September 3, 2002 was performed using by a coarse grid prognostic meteorological model, a fine grid diagnostic meteorological model and a fine grid air dispersion model. Based on the results, we found that the local circulations, like as land-sea breeze, should be seriously considered for evaluating the high PM10 concentration event and for making the reduction policy of the major air pollutant emissions in Ansan area.

Lagrangian Particle Dispersion Modeling Intercomparison : Internal Versus Foreign Modeling Results on the Nuclear Spill Event (방사능 누출 사례일의 국내.외 라그랑지안 입자확산 모델링 결과 비교)

  • 김철희;송창근
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.3
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    • pp.249-261
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    • 2003
  • A three-dimensional mesoscale atmospheric dispersion modeling system consisting of the Lagrangian particle dispersion model (LPDM) and the meteorological mesoscale model (MM5) was employed to simulate the transport and dispersion of non-reactive pollutant during the nuclear spill event occurred from Sep. 31 to Oct. 3, 1999 in Tokaimura city, Japan. For the comparative analysis of numerical experiment, two more sets of foreign mesoscale modeling system; NCEP (National Centers for Environmental Prediction) and DWD (Deutscher Wetter Dienst) were also applied to address the applicability of air pollution dispersion predictions. We noticed that the simulated results of horizontal wind direction and wind velocity from three meteorological modeling showed remarkably different spatial variations, mainly due to the different horizontal resolutions. How-ever, the dispersion process by LPDM was well characterized by meteorological wind fields, and the time-dependent dilution factors ($\chi$/Q) were found to be qualitatively simulated in accordance with each mesocale meteorogical wind field, suggesting that LPDM has the potential for the use of the real time control at optimization of the urban air pollution provided detailed meteorological wind fields. This paper mainly pertains to the mesoscale modeling approaches, but the results imply that the resolution of meteorological model and the implementation of the relevant scale of air quality model lead to better prediction capabilities in local or urban scale air pollution modeling.

Sensitivity Analysis of Air Pollutants Dispersion Model in the Road Neighboring Area Due to the Line Source -The Object on ISCST3, CALINE4 Model- (선 오염원에 의한 도로변 지역으로의 대기확산모델의 민감도 분석 - ISCST3, CALINE4 모델을 중심으로 -)

  • Ahn, Won-Shik;Park, Myung-Hee;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.16 no.6
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    • pp.715-723
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    • 2007
  • The air pollutant emission is mainly caused by line sources in urban area. For example, the annually totaled air pollutant emission is known to consist of about 80% of line sources in Daegu. Hence, the appropriate assessment on the air pollutants of line sources is very important for the atmospheric environmental management in urban area. In this study, we made a comparative study to evaluate suitable dispersion model for estimating the air pollution from line sources. Two air pollution dispersion models, ISCST3 and CALINE4 were the subject of this study. The results were as follows; In the assessment of air pollution model, ISCST3 was found to have 4 times higher concentration than CALINE4. In addition, actual data obtained by measurement and estimated values by CALINE4 were generally identical. The air pollution assessment based on ISC3 model produced significantly lower values than actual data. The air pollution levels estimated by ISCST3 were very low in comparison with the observational values.

Impact Analysis of Air Quality of Mobile Sources using Microscopic Emission and Dispersion Model (미시적 탄소배출량 및 대기확산 모형을 이용한 이동오염원에 의한 대기 질 영향 분석)

  • Yang, Choong Heon;Yang, Inchul;Yoon, Chun Joo;Sung, Jung Gon
    • International Journal of Highway Engineering
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    • v.15 no.4
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    • pp.167-175
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    • 2013
  • PURPOSES : The objective of this study is to investigate the capability of the combined model of traffic simulation, emission and air dispersion models on the impact analysis of air quality of mobile sources such as vehicles. METHODS : The improvement of the quality of life brings about the increasing interest of the public environment. Many endeavors including the travel demand management, the application of the state-of-the-art ITS technologies, the promotion of eco-friendly vehicles have been tried in transportation area to reduce the modal emissions. Especially, it is expected that the increasing number of eco-friendly vehicles in the road network would be able to reduce the pipe-tail emissions tremendously. From this perspective, we have performed a study on the impact analysis of the popularization of the eco-friendly vehicle in the place of the fossil fuel energy powered vehicles on the surrounding air quality using the combined framework of microscopic traffic simulation, emission and air dispersion model. RESULTS : The combined model successfully captured the effect of moving to the eco-friendly vehicles on the air quality, and the results showed that the increasing usage of eco-friendly vehicles can improve the surrounding air quality tremendously and that the air dispersion model plays a crucial role in the investigation of the air quality change around the main corridor. CONCLUSIONS : This study demonstrated the capability of the combined model showing the spatio-tempral change of emission concentration.

Sensitivity of Air Pollutants Dispersion According to the Selection of Meteorological Data - Case of Seongseo Industrial Complex of Daegu - (기상자료에 따른 대기오염확산 민감도평가 -대구성서산업단지에 대한 사례연구-)

  • Park Myung-Hee;Kim Hae-Dong;Park Mi-Young
    • Journal of Environmental Science International
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    • v.14 no.2
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    • pp.141-156
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    • 2005
  • The importance of atmospheric conditions for the assessment of an air pollution situation has been demonstrated by their influence on the various compartments of an air pollution system, comprising all stages from emission to effects. Especially, air pollutants dispersion phenomenon are very sensitive according to wind data. But the discussions of how to apply representative meteorological data in air pollution dispersion model are not frequent in Korean environmental assessment processes. In this study, we investigated the difference of air pollutants dispersion phenomenon using U.S EPA ISCLT3 model according to applying the different meteorological data observed at two points for Seongseo industrial complex of Daegu. Two points are the spot site of Seongseo industrial complex and Daegu meteorological observatory. The winds speed of the spot site were smaller than those of Daegu meteorological observatory. In the winter season, the differences came to about $64\%$ for the period$(I\;February\;2001\~31\;January\;2002)$. Wind directions were also fairly different at two points. The air pollutants dispersion phenomenon estimated from our numerical experiments were also fairly different owing to the meteorological conditions at two points.

The Prediction and Evaluation Air Pollutants Concentration around Industrial Complex by using Atmospheric Dispersion Models -Based on ISCST3, FDM, AERMOD- (대기확산모델을 사용한 공단주변지역의 대기오염물질농도 예측 및 평가 -ISCST3, FDM, AERMOD를 중심으로-)

  • 이화운;원경미;배성정
    • Journal of Environmental Science International
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    • v.8 no.4
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    • pp.485-490
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    • 1999
  • We will calculate concentration of air pollutants using ISCST3, FDM and AERMOD of models recommended in U. S. EPA which are able to predict concentration of short term for point source, complex like industrial complex, power plant and burn-up institution. Before executing model, as analyzing computational result of many cases according to selecting of input data, we will increasing predictable ability of model in limit range of model. Especially, we analyzed three cases-case of considering various emission rate according to time scale and not, case considering effect of atmospheric pollution materials removed by physical process. In our study, after comparing and analyzing results of three model, we choose the atmospheric dispersion model reflected well the characteristic of the area. And we will investigate how large the complex pollutant sources such as industrial complex contribute to atmospheric environment and air quality of the surrounding the area as predicting and estimating chosen model.

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SST Effect upon Numerical Simulation of Atmospheric Dispersion (대기확산의 수치모의에서 SST 효과)

  • 이화운;원경미;조인숙
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.6
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    • pp.767-777
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    • 1999
  • In the coastal region air flow changes due to the abrupt change of surface temperature between land and sea. So a numerical simulation for atmospheric flow fields must be considered the correct fields of sea surface temperature(SST). In this study, we used variables such as latent heat flux, sensible heat flux, short and long wave radiation of ocean and atmosphere which exchanged across the sea surface between atmosphere and ocean model. We found that this consideration simulated the more precise SST fields by comparing with those of the observated results. Simulated horizontal SST differences in season were 2.5~4$^{\circ}C$. Therefore we simulated the more precise atmospheric flow fields and the movement and dispersion of the pollutants with the Lagrangian particle dispersion model. In the daytime dispersion pattern of the pollutants emitted from ship sources moved toward inland, in the night time moved toward sea by land/sea breeze criculation. But air pollutants dispersion can be affected by inland topography, especially Yangsan and coastal area because of nocturnal wind speed decrease.

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Lagrangian Particle Model for Dense Gas Dispersion (고밀도 가스 확산 예측을 위한 라그란지안 입자 모델)

  • Ko, S.;Lee, C.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.899-904
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    • 2003
  • A new model for dense gas dispersion is formulated within the Lagrangian framework. In several accidental released situations, denser-than-air vapour clouds are formed which exhibit dispersion behavior markedly different from that observed for passive atmospheric pollutants. For relevant prediction of dense gas dispersion, the gravity and entrainment effects need to implemented. The model deals with negative buoyancy which is affected by gravity. Also, the model is subjected to entrainment. The mean downward motion of each particle was accounted for by considering the Langevin equation with buoyancy correction term.

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A Development of Air Dispersion Modeling Software, AirMaster (대기확산 모델링 Software, AirMaster 개발)

  • Koo, Youn-Seo;Yoon, Hee-Young;Kim, Sung-Tae;Jeon, Kyung-Seok;Park, Sung-Soon;Kweon, Hee-Yong;Hwang, Ju-Hyun;Kim, Jong-Hwa;Choi, Jong-Keun;Lee, Im-Hak
    • Journal of Environmental Impact Assessment
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    • v.9 no.4
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    • pp.323-338
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    • 2000
  • A Korean air dispersion modeling software, AirMaster, was developed on a basis of dispersion theories adopted in U.S. EPA's ISC3 (Industrial Source Complex - version 3) model to assess the air quality impact from the stacks. Key characteristics of AirMaster are as follows: 1) The building downwash effect can be easily simulated; 2) The screen, long term, and short term models can be run independently; 3) The input data to run the model such as meteorological and terrain data are supplied automatically from the databases in AirMaster; and 4) The modeling procedure is easy and simple under the GUI window environment. In order to validate AirMaster, comparisons with ISC3 model and Indianapolis tracer experiment were carried out. It was shown that AirMaster was identical to ISCST3 and ISCLT3 models in predicting the 1 hr to annual concentrations from the stack under various stack emission and meteorological conditions. The 1 hr concentrations predicted by AirMaster also showed a good agreement with the Indianapolis tracer measurements.

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A CFD Study of Roadside Barrier Impact on the Dispersion of Road Air Pollution

  • Jeong, Sang Jin
    • Asian Journal of Atmospheric Environment
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    • v.9 no.1
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    • pp.22-30
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    • 2015
  • This study evaluated road shape and roadside barrier impact on near-road air pollution dispersion using FLUENT computational fluid dynamics (CFD) model. Simulated road shapes are three types, namely at-grade, depressed, and filled road. The realizable k-${\varepsilon}$ model in FLUENT CFD code was used to simulate the flow and dispersion around road. The selected concentration profile results were compared with the wind tunnel experiments. The overall concentration profile results show good agreement with the wind tunnel results. The results showed that noise barriers, which positioned around the at-grade road, decrease the horizontal impact distance (In this study, the impact distance was defined as the distance from road surface origin coordinate to the position whose mass fraction is 0.1.) lower 0.33~0.65 times and change the vertical air pollution impact distance larger 2.0~2.27 times than those of no barrier case. In case of filled road, noise barriers decrease the horizontal impact distance lower 0.24~0.65 times and change the vertical air pollution impact distance larger 3.33~3.55 times than those of no barrier case. The depressed road increase 1.53~1.68 times the vertical air pollution impact distance. It contributes the decrease of horizontal air pollution impact distance 0.32~0.60 times compare with no barrier case.