• 해양환경안전학회지
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• 제24권7호
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• pp.841-847
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• 2018

세계 에너지 소비와 에너지 수요가 급격히 증가함에 따라 환경문제와 지속가능성에 대한 관심이 요즘 더욱 중요해지고 있다. 신재생에너지 중 해상풍력발전과 같은 깨끗하고 재생가능한 에너지자원은 대체에너지 자원으로 주목받고 있다. 유지보수 및 운영상의 관점에서 해상풍력발전은 일반적으로 연근해해역에 설치될 계획이지만 해상풍력발전단지의 개발은 계획된 풍력단지를 따라 기존의 해상교통으로부터 다양한 해상교통 간섭에 직면해 있는 실정이다. 해상풍력발전단지 인근해역 및 단지 내에서 해상교통을 안전하고 효과적으로 통제하기 위해 선박이 해상풍력단지 내에서 통항할 수 있도록 표준 기준을 제안한다. 따라서, 본 연구의 목적은 국외 해상풍력발전단지의 현지 규정을 조사하여 해상풍력발전단지에 대한 선박통항 허용 및 안전구역 기준을 수립 하는데 있다. 풍력단지의 내측 안전구역은 풍력터빈 날개 회전직경의 150 %를 적용한 거리와 외측안전구역으로는 외곽에 위치한 풍력터빈으로부터 200 m의 범위의 거리를 제시하였으며, 또한 풍력단지 내 선박통항 허용기준은 풍력터빈 날개의 높이와 조위를 평가하여 향후 서남해 해상풍력발전단지의 실증단지 해역에서 Air draft 14.47 m가 선체 접촉을 피할 수 있는 최소 마진을 가진 기준을 제시하였다. 향후 연구과제로서, 단일 해상풍력단지 내의 선박 통항 기준과 더불어 인접한 해상풍력단지 간의 선박통항 기준마련을 위한 후속연구가 필요하다.

• 한국대기환경학회지
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• 제14권5호
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• pp.479-490
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• 1998

The concentrations of ten inorganic (sodium, chloride, sulfate, ammonia, etc.) and three organic (acetate, formate, and MSA) ions associated with airborne particulate matter were measured from Cheju Island, Korea during the three field intensive campaigns conducted in (1) Sept./oct. 1997 (fall), (2) Dec. 1997 (winter), and (3) April 1998 (spring). The results of our measurements indicated that the concentration levels of most ionic species were decreasing significantly across the three experimental periods. The patterns of concentration reduction were clear as the sum of all cation and anion species changed dramatically across those periods such as 294> 144 > 65 and 193 >96>74 nequiv/m3, respectively. The changes were best explained in terms of the wind rose patterns of the study site. Since our sampling spot is located on the western-end point of Cheju Island, it is likely to reflect the effects of diverse sources such as natural, marine processes during NW and local non-maritime ones during SE winds. .Hence, the periodical changes in ionic concentrations may be accounted for by the comparable changes in wind direction. To further investigate environmental characteristics of these ionic components, correlation analysis was conducted not only between meteorological and ion data but between different ion-pairs. The results of these analyses confirm that the concentration levels of ionic species are strongly affected by wind speed and temperature and that there are certain patterns between ion species to which such effects apply. In light of the significance of the wind rose patterns in the area, we further extended these analyses into four data groups that were divided on the basis of wind direction. The results of these analyses showed that the strength of correlations between important pairs (e.g.:. between windspeed and most of major inorganic species including sodium and chloride) can be ranked on the distribution of major ions are very diverse, depending on data grouping scheme for such analysis. The results of this study thus suggest that environmental behavior of chemical components be analyzed in various respects, rather than simple standard, especially if measurements are made in complex environmental condition under which both natural and anthropogenic effects are competing each other.

• 한국대기환경학회지
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• 제25권4호
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• pp.289-303
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• 2009

The chemical and meteorological effects on the concentration variations of ozone ($O_3$) were evaluated based on the intensive air quality measurement (5 pollutants and aromatic volatile organic compounds (AVOCs)) in and out-side an urban valley during spring and summer of 2006. The 5 pollutants measured in the study area include $O_3$, $NO_2$, NO, $PM_{10}$, and CO; the AVOCs include benzene (BEN), toluene (TOL), ethylbenzene (EB), m,p-xylene (MPX), and o-xylene (OX). For the purpose of this study, study areas were classified into two categories: valley area (VA) with a semi-closed topography covering a number of industrial complex, public building, and mountains and non-valley area (NVA) surrounding the suburban and residential areas. In general, the mean concentration levels of most pollutants (except for $PM_{10}$) in the VA were higher than those in the NVA. It was found that the average $O_3$ increase in the VA during spring might result from the combined effects such as the photochemical production from diverse anthropogenic sources and the $O_3$ accumulation due to geographical features (e.g., the semi-closed topography) and wind conditions (e.g., a low wind speed). In addition, the nocturnal $O_3$ increase in the VA during spring was primarily caused by local wind conditions (e.g., mountain and valley winds) with the low wind speed (approximately $1{\sim}2\;m\;s^{-1}$). On the other hand, the $O_3$ difference between the two areas during summer might be because of the photo-chemical production with the $O_3$ precursors (especially the AVOCs) rather than the contribution of wind conditions.

• 한국대기환경학회지
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• 제32권3호
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• pp.329-341
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• 2016

Pohang is a well-known industrial city in Korea with a large steel-industrial complexes. The biggest environmental issue in the city is associated with fine particulate matter (hereinafter, $PM_{10}$). The concentration of $PM_{10}$ is generally dependent on the local emission sources and meteorological conditions. Iron and steel industrial complexes are likely serious pollution sources of $PM_{10}$ in Pohang. In this study, daily $PM_{10}$ data from a large database from the year of 2000 to 2012 were statistically analyzed, together with meteorological data. The average concentrations of $PM_{10}$ were evaluated according to the frequency of Asian dust, haze, mist, and fog. The number of days exceeding short-term standard for $PM_{10}$ were also examined, taking into consideration of weather conditions. It was found that the concentration of $PM_{10}$ was reduced about 18% to 26% because of precipitation. In addition, the effects of wind direction and wind speed on the $PM_{10}$ concentrations were investigated.

• 한국환경보건학회지
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• 제30권5호
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• pp.417-426
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• 2004

We investigate changing characteristics and concentration distribution of ambient air quality using data from which obtained local ambient air monitoring network and local meterological measuring sites in Gwangju area from January to December in 2003. Sulfur dioxide ($SO_2$) showed that increase from 8 AM and decrease in 6 PM but, it was not drastically changed concentration. it also 0.010 ppm in 1995 from at this time it's decrease step by step and than some constant in year 2001 to 2003. Nitrogen dioxide ($NO_2$) concentration was showed highest peak in 10 AM and increase again at 6 PM. And also it showed peak concentration (0.026 ppm) in 2001 and decreased from after that times. Ozone was showed peak concentration in 1 PM and Nitrogen dioxide was ditto in 10 AM from this data, we can conclude that this two article ws showed chemical reaction by 3 to 5 hours. There was no case of Ozone alarm in Gwangju area since 1995, but it showed highest ozone concentration (over 0.070 ppm) in May and June of the year and 2 to 4 PM of the day and sometimes it showed increase at the dawn. Ozone product optimum condition was that air temperature is over $25^{\circ}C$, no rain and increase solar radiation (over $20MJ/m^2$) and no wind or below 2.0 m/s wind speed.

• 한국지구과학회지
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• 제24권6호
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• pp.533-548
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• 2003

지표 및 연직기상자료를 이용하여 포항지역 주변의 겨울철 탁월풍 현상을 살펴보고 이 현상을 분석하기 위해 RAMS를 이용한 수치모의를 수행하였다. 조사결과, 상층대기에서는 서풍을 보였으나 지표부근에서는 남서풍이 탁월하였다. RAMS를 이용하여 겨울철 풍계를 살펴본 결과, 이러한 겨울철 탁월풍 현상은 해안선의 형태와 낮은 구릉지, 그리고 바다와 육지의 분포 등의 지형적 특징에 의해 크게 영향을 받는 것으로 분석되었다. 이상의 모형결과의 정확성을 살펴보기 위해 일 중 지속적인 남서풍이 관측되었던 날들의 풍속, 기온, 풍향을 대상으로 관측값과 모형결과값을 비교하였다. 일반적으로 기상관측망은 공간적으로 조밀하지 못하기 때문에 국지순환계의 특징을 자세히 살펴보기가 쉽지 않다. 하지만 이러한 공간적 고분해능을 만족하는 수치모형을 이용한다면 더욱 정확한 결과를 제공받을 수 있을 것이다.

• Wind and Structures
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• 제28권2호
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• pp.129-140
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• 2019

Accurately simulating the wind field of large-scale region, for instant urban areas, the locations of large span bridges, wind farms and so on, is very difficult, due to the complicated terrains or land surfaces. Currently, the regional wind field can be simulated through the combination of observation data and numerical model using observation-nudging in the Weather Research and Forecasting model (WRF). However, the main drawback of original observation-nudging method in WRF is the effects of observation on the surrounding field is fully mathematical express in terms of temporal and spatial, and it ignores the effects of terrain, wind direction and atmospheric circulation, while these are physically unreasonable for the turbulence. For these reasons, a spatial correlation-based observation-nudging method, which can take account the influence of complicated terrain, is proposed in the paper. The validation and comparation results show that proposed method can obtain more reasonable and accurate result than original observation-nudging method. Finally, the discussion of wind field along bridge span obtained from the simulation with spatial correlation-based observation-nudging method was carried out.

• 환경영향평가
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• 제15권4호
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• pp.237-247
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• 2006

In case of studied area located around the sea, the data measured from the regional meteorological office is highly different from the local weather data because the diffusivity of fugitive dust varies considerably with meteorological conditions. Especially, it is very difficult to predict the amount of fugitive dust accurately as wind speed remains high frequently. In this study, the fluxes of suspended particulates as a function of the friction velocity were applied to consider the effect of wind speed on the amount of fugitive dust generated from the reclamation site. The amount of fugitive dust estimated as mentioned above was simulated by using ISCST3 model. As a result, in case of using only the Fugitive Dust Formula which is usually used in Environment Impact Assessment, the predicted $PM_{10}$ concentrations with points were $43.4{\sim}67.8{\mu}g/m^3$. However, in case of applying to the flux of suspended particulates, the predicted values of $PM_{10}$ with points were $43.3{\sim}69.1{\mu}g/m^3$, $49.5{\sim}90.4{\mu}g/m^3$ and $76.0{\sim}182.6{\mu}g/m^3$ with the wind speeds of 4.4, 5.8 and 7.7m/s, respectively. It could be possible to predict the amount of fugitive dust accurately because these predicted values were similar to the measured values. Consequently, we can establish alternatives for reduction of fugitive dust in this area damaged by fugitive dust which is caused by wind.

• 한국환경과학회지
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• 제22권9호
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• pp.1213-1226
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• 2013

$PM_{10}$ concentration is related to the meteorological variables including to local and synoptic meteorology. In this study the $PM_{10}$ concentrations of Busan in 2007~2011 were analyzed and the days of yellow sand or rainfall which is more than 5 mm were excluded. The sections of $PM_{10}$ concentration were divided according to 10-quantiles, quartiles and 90-quantiles. The 90-quantiles of daily $PM_{10}$ concentration were selected as high concentration dates. In the high concentration dates the daily mean averaged cloudness, mean daily surface wind speed, daily mean surface pressure and PBL height were low and diurnal variation of surface pressure and daily maximum surface temperature were high. When the high $PM_{10}$ dates occurred, the west and south wind blew on the ground and the west wind blew strongly on the 850 hPa. So it seemed that long range transboundary air pollutants made effects on the high concentration dates. The cluster analysis using Hysplit model which is the backward trajectory was made on the high concentration dates. As a result, 3 clusters were extracted and on the short range transboundary cluster the daily mean relative humidity and cloudness were high and PBL height was low.

• 한국대기환경학회지
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• 제27권6호
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• pp.791-804
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• 2011

Numerical simulations were carried out to investigate the impact of PBL (Planetary boundary layer) scheme implemented in WRF on the result of meteorological fields and CMAQ modeling. 25-day period, representing high ozone concentration, was selected for the simulations. The three WRF domains covered East Asia region, Korean Peninsula and Seoul metropolitan area. The sensitivity of WRF-CMAQ modeling to the various PBL schemes was assessed and quantified by comparing model output and against observation from the meteorological and the air quality monitoring network within the domain. The meteorological variables evaluated included temperature, wind speed and direction over surface sites and upper air sounding sites. The CMAQ variables included gaseous species $O_3$ and $NO_x$ over monitoring stations. Although difference of PBL schemes implemented in WRF, they did not appreciably affect the WRF and CMAQ performance. There are partially differences between non-local and local mixing scheme, but are not distinct differences for the results of weather and air quality. It is suggested that impact of parameterization of vertical eddy diffusivity scheme in CMAQ also need to be researched in the future study.