본 연구의 목적은 휘발성 유기화합물(VOC)과 먼지(PM)의 배출원 프로파일로부터 화학종 분류를 할당하고, 성김 행렬 조작자 핵심 배출량 시스템(SMOKE) 내에 배출원 분류코드에 따른 배출원 프로파일의 화학종 분류와 시간분배계수를 수정하는 것이다. 기솔린, 디젤 증기, 도장, 세탁, LPG 등과 같은 VOC 배출원 프로파일로부터 화학 종 분류는 탄소 결합 IV (CBIV) 화학 메커니즘과 주 규모 대기오염연구센터 99 (SAPRC99) 화학 메커니즘을 위해 각각 12종과 34종을 포함한다. 또한 토양, 도로먼지, 가솔린, 디젤차, 산업기원, 도시 소각장, 탄 연소 발전소, 생체 연소, 해안 등과 같은 PM2.5 배출원 프로파일로부터 화학종 분류는 미세 먼지, 유기탄소, 원소 탄소, 질산염과 황산염의 5종으로 할당하였다. 게다가 점 및 선 배출원의 시간 프로파일은 2007년 수도권 지역에서의 굴뚝 원격감시시스템(TMS)과 시간별 교통 흐름 자료로부터 구하였다. 특별히 점 배출원에 있어 오존 모델링을 위한 시간분배계수는 굴뚝 원격감시시스템 자료의 NOX 배출량 인벤토리에 근거하여 추정하였다.
The purpose of this study was to assess an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Using a mass balance model and regression analysis, penetration factor and source strength factor were calculated using multiple indoor and outdoor measurements. This study was performed in 30 selected apartments in Seoul, Asan, and Daegu area which were constructed within 4 years and over 4 years, to measure the concentration of NO2 from July, 2004 to September. The results of this study are as follows. The average concentration of NO2 in Seoul, Asan, and Daegu area in the apartment constructed within 4 years are nitrogen dioxide 48.01㎍/m3 and in the apartment over 4 years are nitrogen dioxide 46.54㎍/m3. Mean ratios of indoor to outdoor NO2 concentrations are Seoul 0.99, Asan 0.83, Daegu 1.18. The deposition constant and the source strength of NO2 were 0.97±0.55 hr-1 and 16.33±12.30 ppb/h, respectively. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.
In this study, to investigate an optimal configuration method for the modeling system, we performed an optimization experiment by controlling the types of compilers and libraries, and the number of CPU cores because it was important to provide reliable model data very quickly for the national air quality forecast. We were made up the optimization experiment of twelve according to compilers (PGI and Intel), MPIs (mvapich-2.0, mvapich-2.2, and mpich-3.2) and NetCDF (NetCDF-3.6.3 and NetCDF-4.1.3) and performed wall clock time measurement for the WRF and CMAQ models based on the built computing resources. In the result of the experiment according to the compiler and library type, the performance of the WRF (30 min 30 s) and CMAQ (47 min 22 s) was best when the combination of Intel complier, mavapich-2.0, and NetCDF-3.6.3 was applied. Additionally, in a result of optimization by the number of CPU cores, the WRF model was best performed with 140 cores (five calculation servers), and the CMAQ model with 120 cores ( five calculation servers). While the WRF model demonstrated obvious differences depending on the number of CPU cores rather than the types of compilers and libraries, CMAQ model demonstrated the biggest differences on the combination of compilers and libraries.
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.
In order to improve the prediction of the regional air quality modeling in the Seoul metropolitan area, a sensitivity analysis using two PBL and microphysics (MP) options of the WRF model was performed during four seasons. The results from four sets of the simulation experiments (EXPs) showed that meteorological variables (especially wind field) were highly sensitive to the choice of PBL options (YSU or MYJ) and no significant differences were found depending on MP options (WDM6 or Morrison) regardless of specific time periods, i.e. day and night, during four seasons. Consequently, the EXPs being composed of YSU PBL option were identified to produce better results for meteorological elements (especially wind field) regardless of seasons. On the other hand, the accuracy of all simulations for summer and winter was somewhat lower than those for spring and autumn and the effect according to physics options was highly volatile by geographical characteristics of the observation site.
The extreme weather conditions negatively affect the traffic flow performance, and the change of traffic systems has significant impacts on the air pollutant emission. This study identifies the correlation between rainfall, traffic volume, travel speed and air pollution concentration (NO2 and PM10) in Seoul. We employed a path analysis using rainfall data from Korea Meteorological Administration and Seoul’s air quality and traffic monitoring data in July and August on 2014. It is found that the occurrence of rainfall decreases NO2 and PM10 concentration due to the higher washing effect, while rainfall increases NO2 and PM10 concentration via the changes in traffic volume and traffic speed. The analysis of the rainfall intensity reveals that the rainfall increases NO2 concentration due to the traffic volume increase and the traffic speed reduction if an hourly rainfall is more than 5mm. It is to note that the current model succeeds in identifying the relationship between weather conditions, traffic flow performance and air pollution in a unified and consistent framework, which can be used for better predicting the changes in air pollution concentration.
The objective of this work is the air quality modeling according to the scenarios of emission on complex terrain. The prognostic meteorological fields and air quality field over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model (MM5) and the Third Generation Community Multi-scale Air Quality Modeling System (Models - 3/CMAQ), respectively. The emission source was driven from the Clean Air Policy Support System of the Korea National institute of Environmental Research (CAPSS), which is a 1 km x 1 km grid in South Korea during 2003.
In comparison of air quality fields, the simulated averaged PM10, NO2, and O3 concentration on complex terrain in control case were decreased as compared with base case. Particularly PM10 revealed most substantial localized differences by (18 ~ 24 μg/m3). The reduction rate of PM10, NO2, and O3 is respectively 18.88, 13.34 and 4.17%.
Indoor air quality is the dominant contributor to total personal exposure because most people spend a majority of their time indoors. Especially when indoor environments have sources of contaminants, exposure to indoor air can potentially pose a greater threat than exposure to ambient air. In this study, estimations of volatile organic compounds and formaldehyde emission rate in indoor environments of new apartments were carried out using mass balance model in indoor environment, because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. Considering the estimated emission rate of volatile organic compounds and formaldehyde, it is suggested that new apartment should be designed and constructed in the aspect of using construction materials to emit low hazardous air pollutants.