• 한국대기환경학회지
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• 제15권5호
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• pp.625-638
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• 1999

Air quality modeling for coastal urban region has been composed of a complex system including meteorological, chemical and physical processes and emission characteristics in complex terrain. In this study, we studied about an effect prediction for deposition phenomenon affecting on air quality in Pusan metopolitan metropolitan city. In air quality modeling including ship sources, a situation considered deposition process habe better result than not considered when compared with observed value. Air pollutants emitted into urban air during the daytime nearly removed through urban atmosphere polluted. Also these phenomena correlated concentration variation connent with sea/land breezes and terrain effect. Therefore we conclude that the concentration was low at daytime when deposition flux is high, and deposition effect on industrial complex and Dongrae region is considerable in particular.

• 한국대기환경학회지
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• 제27권1호
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• pp.30-40
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• 2011

Numerical simulations were carried out to investigate the impact of SST spatial distribution on the result of air quality modeling. Eulerian photochemical dispersion model CAMx (Comprehensive Air quality Model with eXtensions, version 4.50) was applied in this study and meteorological fields were prepared by RAMS (Regional Atmospheric Modeling System). Three different meteorological fields, due to different SST spatial distributions were used for air quality modeling to assess the sensitivity of CAMx modeling to the different meteorological input data. The horizontal distributions of surface ozone concentrations were analyzed and compared. In each case, the simulated ozone concentrations were different due to the discrepancies of horizontal SST distributions. The discrepancies of land-sea breeze velocity caused the difference of daytime and nighttime ozone concentrations. The result of statistic analysis also showed differences for each case. Case NG, which used meteorological fields with high resolution SST data was most successfully estimated correlation coefficient, root mean squared error and index of agreement value for ground level ozone concentration. The prediction accuracy was also improved clearly for case NG. In conclusion, the results suggest that SST spatial distribution plays an important role in the results of air quality modeling on high ozone episode at coastal region.

• 한국대기환경학회지
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• 제29권4호
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• pp.407-438
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• 2013

Current status and future direction of air quality modeling for monitoring and forecasting air quality in East Asia were discussed in this paper. An integrated air quality modeling system, combining (1) emission processing and modeling, (2) meteorological model simulation, (3) chemistry-transport model (CTM) simulation, (4) ground-based and satellite-retrieved observations, and (5) data assimilation, was introduced. Also, the strategies for future development of the integrated air quality modeling system in East Asia was discussed in this paper. In particular, it was emphasized that the successful use and development of the air quality modeling system should depend on the active applications of the data sets from incumbent and upcoming LEO/GEO (Low Earth Orbit/Geostationary Earth Orbit) satellites. This is particularly true, since Korea government successfully launched Geostationary Ocean Color Imager (GOCI) in June, 2010 and has another plan to launch Geostationary Environmental Monitoring Spectrometer (GEMS) in 2018, in order to monitor the air quality and emissions in/around the Korean peninsula as well as over East Asia.

• 한국환경과학회지
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• 제11권9호
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• pp.933-943
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• 2002

The urban pollution if affected by local environmental, so it is necessary to consider area characteristics such as emission source and meteorological phenomena, in studying urban air pollution. Ulsan is laocated on south-east coast and has many industrial facilities, so many people have concerned about air pollution. This study contain conducting numerical simulation of air pollutant concentration considered land and sea breeze in Ulsan area with the numerical model.

• 한국대기환경학회지
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• 제26권6호
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• pp.591-605
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• 2010

Recirculation of airmass in coastal region occurs because of the change from land to sea breeze and was shown to produce a contrary result on air quality. This study examines the numerical simulation to analyze the effect of recirculation flow in Gwangyang Bay, Korea. For this purpose two case studies are performed by the WRF-FLEXPART-CMAQ modeling system, each for a different Meso-Synoptic Index. Additionally this research make a comparative study of large domain (Domain L) and small domain (Domain S). The horizontal wind fields are simulated from WRF. Changes in the land-sea breeze have an effect on the particle dispersion modeling. The numerical simulation of air quality is carried out to investigate the recirculation of ozone. Ozone is transported to eastward under strong synoptic condition (Case_strong) because of westerly synoptic flow and this pattern can confirm in all domain. However ozone swept off by the land breeze and then transported to northward along sea breeze under conditions of clear sky and weak winds (Case_weak). In this case re-advected ozone isn't simulate in Domain S. The study found that recirculation of airmass must be concerned when numerical simulation of air quality is performed in coastal region, especially on a sunny day.

• 한국대기환경학회지
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• 제17권4호
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• pp.331-345
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• 2001

The increase of carbon monoxide in the ambient air due to the emissions from point sources without control was estimated using three -dimensional numerical models. The target area was Ulsan where one of the largest industrial complexes was located. As a typical example using numerical models for air quality impact analysis of criteria pollutants that will determine whether the air quality standards would be exceeded or not, the following approaches were suggested. They include: (1) investigation of pre-existing atmospheric conditions, (2) identification of major factors causing high concentrations, (3) selection of episode days. (4) preparation of three-dimensional meteorological data, (5) confirmation of agreement between measured and predicted concentrations in the emission conditions of episode days, and (6) estimation of the impact due to changes of the emission conditions. In the present work, daily meteorological conditions for the specific period were classified into four clusters of distinctive features, and the episode days were selected individually from each cluster. Emphasis was placed on the selection of episodes representing meteorological conditions conducive to high concentrations especially for point sources that were sensitive to the wind direction variations.

• 한국환경과학회지
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• 제25권7호
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• pp.1029-1042
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• 2016

The initial and boundary conditions are important factors in regional chemical transport modeling systems. The method of generating the chemical boundary conditions for regional air quality models tends to be different from the dynamically varying boundary conditions in global chemical transport models. In this study, the impact of real time Copernicus atmosphere monitoring service (CAMS) re-analysis data from the modeling atmospheric composition and climate project interim implementation (MACC) on the regional air quality in the Korean Peninsula was carried out using the community multi-scale air quality modeling system (CMAQ). A comparison between conventional global data and CAMS for numerical assessments was also conducted. Although the horizontal resolution of the CAMS re-analysis data is not higher than the conventionally provided data, the simulated particulate matter (PM) concentrations with boundary conditions for CAMS re-analysis is more reasonable than any other data, and the estimation accuracy over the entire Korean peninsula, including the Seoul and Daegu metropolitan areas, was improved. Although an inland area such as the Daegu metropolitan area often has large uncertainty in PM prediction, the level of improvement in the prediction for the Daegu metropolitan area is higher than in the coastal area of the western part of the Korean peninsula.

• 한국대기환경학회지
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• 제19권1호
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• pp.13-23
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• 2003

A local wind model and a three dimensional local environmental model including advection, diffusion, deposition. and photochemical reactions were performed at Gwangyang Bay, Korea, to predict air flow and air pollutants concentrations. A large grid was used, and nesting method was employed for small grid calculation. From the meterological module simulation, we were able to reproduce local wind characteristics such as sea/land winds and mountain/valley winds simulation at Gwangyang Bay. In addition, the concentration module showed high concentration regions at Yosu industrial complex, Gwangyang steel company. and Container anchor. It was also seen that air pollutants were dispersed by sea/land winds. A comparison between the measurement and the prediction of sulfur dioxide and nitric oxide, which are relatively low-reacted pollutants, was performed. However, the measured nitrogen dioxide and ozone concentrations were higher than the simulated ones. Particularly, ozone concentration between 8 a..m. and 8 p.m. agreed well, but the measured ozone during the rest of time were generally higher.

• 한국대기환경학회지
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• 제19권3호
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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.

• 한국대기환경학회지
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• 제24권2호
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• pp.259-270
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• 2008

The regional air movement in a coastal area is generated by the different heat capacities of sea and land sides, which is called sea/land breeze. In the west coast area, the local air quality is significantly influenced by this sea/land breeze. In this study, the mathematical model is proposed to estimate the effective area of sea/land breeze. A commercial air model, that is suggested as an alternative air model by USEPA, is introduced to simulate the mechanism of sea/land breeze generation. From this study, it is confirmed that the numerical approach proposed in this study is reliable to predict the effective area of sea breeze in a coastal area. It implies that the current application of common air model needs to be carefully reviewed especially when dealing with a coastal air quality issue. It is also found that the sea breeze in Incheon area has the impact in the range of approximately 24 km in-land side, so-called penetration length.