• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.15-24
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• 2014

The capital city of Himalayan Country Nepal, Kathmandu Valley is surrounded by consecutive high mountains, which limits the air distribution and mixing effects significantly. It in turn generates steady air flow pattern over a year except in monsoon season. The air shed in the Valley is easily trapped by the surrounded mountains and the inversion layer formulated as the cap. The $PM_{10}$ concentration was noticeably higher than the standard level (120 ${\mu}g/m^3$) in urban and suburban area of Kathmandu valley for all seasons except monsoon period. The Valley area experiences similar wind patterns (W, WWS, and S) for a year but the Easterly wind prevails only during the monsoon period. There was low and calm wind blows during the winter season. Because of this air flow structure, the air emission from various sources is accumulated within the valley air, high level of air pollution is frequently recorded with other air polluted cities over the world. In this Valley area, brick kilns are recognized as the major air pollution source followed by vehicles. Mostly Bull Trench Kiln (BKT), Hoffman Kiln and Vertical Shaft Brick Kiln (VSBK) are in operation for brick firing in Kathmandu valley where the fuels such as crushed coal, saw dust, and natural gas are used for processing bricks in this study. Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) was used for screening and quantifying the potential impacts of air emission from firing fuels. The total Environmental Performance Score (EPS) was estimated and the EPS of coal was approximately 2.5 times higher than those of natural gas and saw dust. It is concluded that the crushed coal has more negative impact to the environment and human health than other fuel sources. Concerning the human health and environment point of view, alternative environment friendly firing fuel need to be used for brick industry in the kiln and the air pollution control devices also need to be applied for minimizing the air emissions from the kilns.

• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.255-273
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• 2018

To develop effective emission abatement strategies for eighteen coal-fired power plants located throughout Korea, power plant emission data and TAPM (The Air Pollution Model) were used to quantify the impact of emission reductions on primary $PM_{10}$ concentrations. TAPM was validated for two separate time periods: a high $PM_{10}$ concentration period from April 7 to 12, 2016, and a low $PM_{10}$ concentration period from June 1 to June 6 2016. The validated model was then used to analyze the impacts of five applicable power plant shut-down scenarios. The results showed that shut-down of four power plants located within the Seoul metropolitan area (SMA) would result in up to 18.9% reduction in maximum $PM_{10}$ concentrations, depending on synoptic conditions. A scenario for the shutdown of a single low stack height with highest-emission power plant located nearest to Seoul showed a small impact on averaged $PM_{10}$ concentrations (~1%) and 4.4% ($0.54{\mu}g/m^3$) decrease in maximum concentration. The scenario for four shutdowns for power plants aged more than 30 years within SMA also showed a highest improvement of 6.4% ($0.26{\mu}g/m^3$ in April) in averaged $PM_{10}$ concentrations, and of 18.9% ($2.33{\mu}g/m^3$ in June) in maximum concentration, showing almost linear relationship in and around SMA. Reducing gaseous air pollutant emissions was also found to be significant in controlling high $PM_{10}$ concentrations, indicating the effectiveness of coreduction of power plant emissions together with diesel vehicle emissions in the SMA. In addition, this study is implying that secondary production process generating $PM_{10}$ pollution may be a significant process throughout most regions in Korea, and therefore concurrent abatement of both gas and particle emissions will result in more pronounced improvements in air quality over the urban cities in South Korea.

• Journal of Environmental Impact Assessment
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• v.18 no.4
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• pp.219-227
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• 2009

Because of urban development and changed land cover types, It is very important to acquire pixel unit of land surface temperature(LST) information when the heat island effect(HIE) of regional area are investigated. The brightness temperature observed by satellite is very useful for assessing the pixel unit of LST distributions for the analysis of thermal environment problems of urban areas. Also, satellite land cover data are very useful to our understanding of surface conditions of study areas. In this study, brightness temperature information of Landsat TM thermal channel was analyzed and compared with land cover information of Jeon-ju city. The atmospheric correction of TM thermal channel carried out to explain for compared LST long term monitoring errors. However, simple estimation and evaluation methods to find a physical relationship between LST from satellite images and in-situ data are compared with reference channel emissivity.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.5
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• pp.687-696
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• 1999

Characteristics of four publicly-available accidental release models, ALOHA, SLAB, HGSYSTEM, and DEGADIS, are compared. These models are world-widely used and recently recommended by the Chemical Dispersion and Consequence Assessment(CDCA) Working Group of the United States as models applicable to generally broad safety-basis documentation applicatons. Four release scenarios are assumed by referring to the usage and storage conditions of toxic substances in the field as well as the USEPA model guideline(1993). Sensitivity of impact radius by varying meteorological conditions is tested in typical and worst-case meteorological conditions. The results show that ALOHA generally gives conservative estimates and the results from HGSYSTEM are sensitive to variations in meteorological conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.1
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• pp.88-95
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• 1989

The aspects of the occurence frequency of $SO_2$ concentration were studied with the observed data in Seoul and the scheme that is capable of estimating not only highest concentration for a variety of averaging times but also concentrations for arbitary occurrence frequency with long term arithmatic mean and geometric standard deviation data, was evaluated. The results of the statistical analysis show that the occurrence frequency is almost log normal except a few cases, and 3rd highest values of daily mean concentration were about 4.2 $\sim$ 5.2 times higher than annual arithmatic mean. The evaluation with the observed hourly concentration shows that the scheme fairly well estimate the short concentration of arbitary occurrence frequence and it can be used for air quality management and environmental impact assessment.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.283-284
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• 2002

투명하고, 과학적으로 소각장을 관리하기 위해서는 소각장에서 배출되는 오염물질이 주변에 미치는 기여 영향도를 정확히 계산할 필요가 있다. 이와 같은 목적으로 현재 국내에서 사용되고 있는 대기환경 영향평가용 software는 미국환경청에서 제작된 software로써 DOS상에서 구동되기 때문에 사용이 불편하고 국내 지형 및 기상조건에 부적합한 문제점을 갖고 있다. 따라서 국내 여건에 적합하고, 사용하기 용이한 Windows GUI(Graphic User Interface)에서 공동되는 평가용 software개발이 필요하다. (중략)

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.294-305
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• 2018

Quantitative assessment on the impact from North Korean emissions to surface particulate matter(PM) concentration in the Seoul Metropolitan Area (SMA), South Korea is conducted using a 3-dimensional chemistry transport model. Transboundary transport of air pollutants and their precursors are important to understand regional air quality in East Asian countries. As North Korea locates in the middle of main transport pathways of Chinese pollutants, quantifiable estimation of its impact is essential for policy making in South Korean air quality management. In this study, the Community Multiscale Air Quality Modeling System is utilized to simulate regional air quality and its sensitivity, using the Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment 2015 and the Clean Air Policy Support System 2013 emissions inventories for North and South Korea, respectively. Contributions were estimated by a brute force method, perturbing 50% of North and South Korean emissions. Simulations demonstrate that North Korean emissions contribute $3.89{\mu}g/m^3$ of annual surface PM concentrations in the SMA, which accounts 14.7% of the region's average. Impacts are dominant in nitrate and organic carbon (OC) concentrations, attributing almost 40% of SMA OC concentration during January and February. Clear seasonal variations are also found in North Korean emissions contribution to South Korea (and vice versa) due to seasonal characteristics of synoptic weather, especially by the change of seasonal flow patterns.

• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.198-210
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• 2010

Precise analysis of local winds for the prediction of atmospheric phenomena in the planetary boundary layer is extremely important. In this study, wind profiler data with fine time resolution and density in the lower troposphere were used to improve the performance of a numerical atmospheric model of a complex coastal area. Three-dimensional variational data assimilation (3DVAR) was used to assimilate profiler data. Two experiments were conducted to determine the effects of the profiler data on model results. First, we performed an observing system experiment. Second, we implemented a sensitivity test of data assimilation intervals to extend the advantages of the profiler to data assimilation. The lowest errors were observed when using both radio sonde and profiler data to interpret vertical and surface observation data. The sensitivity to the assimilation interval differed according to the synoptic conditions when the focus was on the surface results. The sensitivity to the weak synoptic effect was much larger than to the strong synoptic effect. The hourly-assimilated case showed the lowest root mean square error (RMSE, 1.62 m/s) and highest index of agreement (IOA, 0.82) under weak synoptic conditions, whereas the statistics in the 1, 3, and 6 hourly-assimilated cases were similar under strong synoptic conditions. This indicates that the profiler data better represent complex local circulation in the model with high time and vertical resolution, particularly when the synoptic effect is weak.

• Journal of Environmental Impact Assessment
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• v.27 no.3
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• pp.322-333
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• 2018

This study was carried out to measure atmospheric environmental improvement effect and estimate its social benefit of thermal power plants through Environmental Impact Assessment (EIA) for quantitative analysis about operational performances of EIA. In this study, 'EIA outcome' is defined as whether or not the system is implemented, therefore, environmental standard to be followed by each project and consultation contents were compared. In total 60 cases of thermal power plant construction projects that have been consulted over the past 10 years since 2010, major air pollutants have been significantly reduced after the implementation of EIA. The $PM_{10}$ reduced annual 3,745 tons, $NO_2$ by 74,569 tons, and $SO_2$ by 37,647 tons, which were estimated at approximately 240 billion won~5 trillion 967 billion won per year for social benefit. This means the total cost of power plant operations will be cut to 7 trillion 192 billion won~178 trillion 994 billion won over a 30-year period. The reduced amount of air pollutants emitted by energy generation facilities across the country is worth 50%, and its economic value is larger than the annual Current Health Expenditure in Korea. This is meant by the fact that all projects are subject to uniform criteria under the existing relevant regulation, but that each project plans are optimized according to the characteristics of target areas and projects through the process of EIA.

• Journal of Environmental Impact Assessment
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• v.17 no.3
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• pp.201-211
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• 2008

According to IPCC fourth assessment report in 2007, global mean temperatures have risen by 0.74 degrees Celsius over the past 100 years. Moreover, in the recent 25 years, global mean temperatures have risen by 0.45 degrees Celsius, which is 2.4-times larger than those in the past 100 years. The evidences for climate change, such as sea level rise, arctic glacier melt, and desertification in Asia, have occurred and increased over the globe. In Korea, because regional climate has been changed, types of agriculture and fishery should be replaced. And as precipitation pattern behave differently from the past decades, water management would be more difficult, furthermore, atmospheric environment, related to concentrations for ozone, sulfate, etc., could be worse. Nevertheless, we have only focused on greenhouse gas reduction duty for the Convention of Climate Change. Fortunately, in the fourth plan on climate change, we have planned to manage climate change more actively since 2007. In Korea, the emission of carbon dioxide has increased about 1.9-times more, from 311million ton in 1990 to 591million ton in 2004. And also about 2 ppm rise every year for concentrations of carbon dioxide in the atmosphere. As a result, ecosystem, quality of water and atmosphere would be affected. Here, the emission of greenhouse gases over the globe is examined, and the effect of greenhouse gases for climate change is reviewed from the results of previous studies. In addition, the countermeasures of mitigation and adaptation on climate change were discussed for the understanding.