• 한국지구과학회지
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• 제21권3호
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• pp.287-301
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• 2000

본 연구진은 포항지역을 중심으로 1995년부터 1997년의 3년간 오존존데로 관측한 고도별 오존농도 및 오존전량 자료를 이용하여 오존의 수직분포특성에 대한 연구를 수행하였다. 오존의 수직분포를 체계적으로 밝히기 위해, 지상(100m), 대류권(10km), 하부 성층권(20km), 중부 성층권(30km)을 대표 고도로 설정하여 오존농도의 시 ${\cdot}$ 공간적 분포특성에 대한 비교분석을 시도하였다. 지상(100m) 오존의 경우, 포항제철이 인접해 있음에도 불구하고, 전반적으로 청정지역에서와 유사한 농도분포를 유지하였다. 봄과 여름에 높고 가을과 겨울에 낮은 농도분포는 기상인자들과의 상관성을 고려할 때, 대체로 광화학 반응에 의한 결과로 보여진다. 대류권(10km) 및 하부 성층권(20km)의 경우 춘고하저(春高夏低)의 전형적인 북반구 대류권 오존의 시간적 경향성을 나타내었다. 이는 고도별 오존농도간의 분석결과 성층권 오존의 대류권 이동 및 광화학 반응과 역전층 형성에 의한 결과로 추정된다. 중부 성층권(30km) 오존의 경우 지상 오존의 농도분포 경향과 매우 유사한 월주기 및 계절주기를 취하였다. Brewer 분광광도계에 의한 오존전량은 성층권 오존량 (Umkehr 법)에 의해 크게 좌우되며, 오존전량은 유해자외선 (UV-B)과의 상관성은 미미하나, 운량과는 음의 상관성을 갖는 것으로 나타났다. 본 연구의 결과 지상권뿐만 아니라 대류권 및 성층권 오존의 시간적 특성을 이해하는데 있어 포항이 해안도시라는 지리학적인 요인이 매우 중요하다는 점을 확인할 수 있다.

• 한국대기환경학회지
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• 제25권4호
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• pp.264-274
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• 2009

Concentration of Air Quality Models (CMAQ) has a deep connection with emissions and wind fields. In particular the wind field is highly affected by local topography and plays an important role in transport and dispersion of contaminants from the pollution sources. The purpose of this study is to examine the impact of interpolation on Air quality model. This study was designed to evaluate enhancement of MM5 and CMAQ predictions by using Four Dimensional Data Assimilation (FDDA), the SONDE data and the national meteorological station and the MODerate resolution Imaging Spectroradiometer (MODIS). The alternative meteorological fields predicted with and without MODIS data were used to simulate spatial and temporal variations of ozone in combined with CMAQ on June 2006. The result of this study indicated that data assimilation using MODIS data provided an attractive method for generating realistic meteorological fields and dispersion fields of ozone in the Korea peninsular, because MODIS data in 10 km domain are grid horizontally and vertically. In order to ensure the success of Air quality model, it is necessary to FDDA using MODIS data.

• 한국대기환경학회지
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• 제29권4호
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• pp.369-377
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• 2013

The trends of the criteria air pollutants' concentrations over Seoul are reviewed, relative contributions of major sources are discussd, and directions for future air quality management are suggested. It was shown that the yearly average concentrations of the criteria air pollutants except nitrogen dioxide and ozone have decreased significantly over the last three decades. Though the concentration of nitrogen dioxide has not decreased, the concentration of $NO_x$ has decreased significantly. The major reason for the reduction of the criteria air pollutants has been strict government regulations such as establishment of strict emission standards and switch to cleaner fuels. However, it is not clear the major reason (s) for the reduction of the $PM_{10}$ concentration. It is suggested that to further reduce the concentrations of secondary air pollutants such as ozone and $PM_{2.5}$, understanding the major chemical pathways for them is essential. In addition, influence from outside Seoul should be quantified and effectively controlled.

• 자원ㆍ환경경제연구
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• 제30권2호
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• pp.207-235
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• 2021

본 논문은 오존과 미세먼지 수준이 도보, 자가용, 버스, 전철의 통행시간에 미치는 영향을 분석한다. 가구통행실태조사 자료와 SUR 모형을 이용하여 분석한 결과, 대기오염 농도가 높아질수록 자가용 통행시간이 증가하고, 버스의 통행시간이 감소하는 것으로 나타난다. 그러나 대기오염 경보가 발령되면 버스의 통행시간이 증가하는 공익적 행위가 일부 나타나지만, 자가용의 통행시간이 증가하거나 변화가 없고, 전철의 통행시간이 증가하지 않는 것으로 나타난다. 이는 경보의 발령으로 제공되는 정보가 배출 저감을 위한 통행행태 변화보다는 오염상황에의 노출을 줄이는 회피행동에 더 큰 영향을 미쳤음을 시사한다.

• 한국대기환경학회지
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• 제23권3호
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• pp.297-310
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• 2007

Recent evidence has demonstrated that the pollutant recirculation can play an important role in leading to high ozone $(O_3)$ concentrations. In this study, the MM5-CAMx air quality modeling system was applied to simulate the pollutant recirculation and identify the transport of pollution during the high $O_3$ event (the maximum $O_3$ of 195 ppb) observed in the Greater Seoul Area (GSA) on $1{\sim}4$ June in 2004. The results showed a weak northeasterly synoptic wind during the night and early morning moved the air parcels containing the locally emitted urban pollution to the coast, which contributed to enhance $O_3$ formation in the southwest part of the GSA. As the sea breeze developed and started to penetrate inland in the late afternoon, the rapid build-up of $O_3$ concentration was found in the southwest coastal area due to the recirculation of the polluted air loaded with high level $O_3$. The simulated backward trajectories and observations at coastal sites confirmed the recirculation of pollutant with the late sea breeze is the dominant factor affecting the occurrence of high $O_3$ concentrations in the southwestern GSA.

• Asian Journal of Atmospheric Environment
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• 제9권4호
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• pp.259-271
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• 2015

This study conducted analyses on biogenic volatile organic compounds (BVOC) emission sources contributing to urban ozone ($O_3$) concentration in Osaka Prefecture, Japan in summer 2010 by using the Weather Research and Forecasting model (WRF) version 3.5.1 and the Community Multiscale Air Quality model (CMAQ) version 5.0.1. This prefecture is characterized by highly urbanized area with small forest area. The contributions of source regions surrounding Osaka were estimated by comparing the baseline case and zero-out cases for BVOC emissions from each source region. The zero-out emission runs showed that the BVOC emissions substantially contributed to urban $O_3$ concentration in Osaka (10.3 ppb: 15.9% of mean daily maximum 1-h $O_3$ concentration) with day-by-day variations of contributing source regions, which were qualitatively explained by backward trajectory analyses. Although $O_3$ concentrations were especially high on 23 July and 2 August 2010, the contribution of BVOC on 23 July (35.4 ppb: 25.6% of daily maximum $O_3$) was much larger than that on 2 August (20.9 ppb: 14.2% of daily maximum $O_3$). To investigate this difference, additional zero-out cases for anthropogenic VOC (AVOC) emissions from Osaka and for VOC emissions on the target days were performed. On 23 July, the urban $O_3$ concentration in Osaka was dominantly increased by the transport from the northwestern region outside Osaka with large contribution of $O_3$ that was produced through BVOC reactions by the day before and was retained over the nocturnal boundary layer. On 2 August, the concentration was dominantly increased by the local photochemical production inside Osaka under weak wind condition with the particularly large contribution of AVOC emitted from Osaka on the day.

• Asian Journal of Atmospheric Environment
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• 제2권2호
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• pp.81-89
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• 2008

The numerical simulation of wind and ozone ($O_3$) transport in mountainous regions was performed with a computational fluid dynamics technique. A dry deposition model for $O_3$ was designed to estimate $O_3$ deposition in complex terrain, and the qualitative validity of the predicted $O_3$ concentration field was confirmed by comparison with observed data collected with passive samplers. The simulation revealed that wind velocity increases around ridge lines and peaks of mountains. The areas with strong wind corresponded well with the sites of tree decline at high altitudes, suggesting that it is an important factor in the localization of tree/forest decline. On the other hand, there is no direct relationship between forest decline and $O_3$ concentration. The $O_3$ concentration, however, tends to increase as wind velocity becomes higher, thus the $O_3$ concentration itself may be a potential secondary factor in the localized decline phenomena. While the diffusion flux of $O_3$ is not related to localized tree decline, the pattern of advection flux is related to those of high wind velocity and localized tree decline. These results suggest that strong wind with large advection flux of $O_3$ may play a key role in the promotion of tree/forest decline at high mountain ridges and peaks.

• 한국환경과학회지
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• 제32권9호
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• pp.613-626
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• 2023

This study investigates the impact of increased adoption of eco-friendly vehicles on ozone (O₃) concentrations in South Korea, utilizing the community multiscale air quality (CMAQ) model. In the summer of 2017 (June-August), we conducted two experiments: a BASE experiment, representing baseline emissions, and an R_30 experiment, involving a 30% emission reduction due to eco-friendly vehicles. The contrast between these experiments reveals that, while most air pollutants decreased with reduced vehicle emissions, O₃ concentrations surprisingly increased (up to 2.1 parts per billion) across South Korea. A further examination of O₃ concentration changes was conducted by analyzing daytime and nighttime variations as well as wind direction. During the daytime, O₃ concentrations notably rose near metropolitan areas due to reduced O₃ titration (O₃ + NO → O₂ + NO₂) resulting from emission reductions. At nighttime, O₃ concentrations exhibited a greater increase, attributed to the transport of daytime-generated O₃ to rural regions. Notably, the impact of reduced emissions in metropolitan areas on O₃ concentrations in downwind areas varied depending on the prevailing wind direction. These findings highlight that the promotion of eco-friendly vehicles, though effective in lowering certain air pollutants, might not directly influence O₃ concentrations. This study underscores the need to comprehensively understand the complicated chemistry of O₃ to develop effective strategies for air quality management.

• 환경정책연구
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• 제4권1호
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• pp.1-19
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• 2005

금년 1월 1일부터 수도권 대기환경개선에 관한 특별법이 시행되었다. 특별법의 시행으로 정부는 현재 각각 $76{\mu}g/m^3$과 36ppb 수준인 $PM_{10}$과 $NO_2$의 연평균을 10년 내 $40{\mu}g/m^3$과 20ppb까지 낮출 것을 목표하고 있다. 특별법에서는 주로 $PM_{10}$과 $NO_2$와 같은 1차 오염물질만을 언급하고 있으나 정부는 이들의 농도가 낮아짐으로써 고농도 오존과 시정 장애도 개선될 것을 기대하고 있다. 그러나 중국으로부터 오염물질 유입과 광화학반응에 의한 2차 생성으로 인하여 국지 배출 저감에 의한 $PM_{10}$의 농도 감소 효과는 크지 않을 수 있다. 실제 고농도 오존이 빈번한 오존 시즌 동안 수도권 $PM_{10}$의 대부분은 지역규모의 2차 생성 비중이 높은 $PM_{2.5}$이다. 뿐만 아니라 많은 모델링 결과들이 수도권의 상당한 지역에서, $NO_x$를 줄일 경우 오존 농도가 상승하는 소위 '$NO_x$ 불이익' 현상이 나타날 수 있음을 지적하고 있다. 본 논문에서는 수도권의 오염 현황을 살펴보고, 장거리 이동 효과와 광화학 오염 특성 등 이슈와 함께, 특별법의 성공적 이행에 필요한 과제들에 대하여 논의하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.373-377
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• 2002

The Measurement of Pollution in the Troposphere (MOPITT) instrument is an eight-channel gas correlation radiometer launched on the Earth Observing System (EOS) Terra spacecraft in 1999. Its main objectives are to measure carbon monoxide (CO) and methane (CH4) concentrations in the troposphere. This work analyzes tropospheric carbon monoxide distributions using MOPITT data in East Asia and compared ozone distributions. In general, seasonal CO variations are characterized by a spring peak and decreased in the summer. Also, this work revealed that the seasonal cycles of CO are spring maximum and summer minimum with averaged concentrations ranging from 118ppbv to 170ppbv. The CO monthly means show a similar profiles to those of O3. This fact clearly indicates that the high concentration of CO in spring is caused by two possible causes: the photochemical CO production in the troposphere, transport of the CO in the northeast Asia. The CO and O3 seasonal cycles in northeast Asia are influenced extensively by the seasonal exchange of the different types of air mass due to the Asian monsoon. The continental air masses contain high concentrations of O3 and CO due to higher continental background concentrations and sometimes due to the contribution of regional pollution. In summer the transport pattern is reversed. The Pacific marine air masses prevail over Korea, so that the marine air masses bring low concentrations of CO and O3, which tend to give the apparent minimum in summer.