• Title/Summary/Keyword: Sea-breeze

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Numerical Prediction on Snowfall Intensity in the Mountainous Coastal Region

  • Choi, Hyo;Lee, Han-Se;Kim, Tae-Kook;Choi, Doo-Sun
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.89-94
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    • 2003
  • The formation of a severe snow storm occurred in the mountainous coastal region near Mt. Taegualyang and Kangnung city in the eastern part of Korea was investigate from 0900LST, December 7 through 9, 2002, using MM5 model. As synoptic scale easterly wind induced a great amount of moisture from the East Sea into the inland coastal region and sea-breeze further induced more moisture from the basin toward the top of the mountain side. The lifted moisture toward the mountain top was cooled down along the eastern slope of the mountain and near the mid of the mountain the moisture was much cooled down with relative humidity of 100% under the air temperature below $O^{\circ}C$, resulting in the formation of snow. Relative humidity of 100% generally occurred at the 5km away from the coast toward the inland mountain and the band of 100% RH was parallel to the coastal line. The 100% band coincided with minimum air temperature band and line.

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Modeling the effects of land-sea breeze circulation on ozone distribution in coastal urban area. (연안 도시지역 해륙풍순환이 오존분포에 미치는 영향에 관한 수치모의)

  • 황미경;김유근;오인보
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.303-304
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    • 2003
  • 연안도시의 경우 해양 배경농도의 영향과 내륙과 비교해 강한 풍속조건이 형성됨으로 오존농도의 일변화 폭이 적으며 야간에 농도상승 현상이 빈번히 나타난다. 또한 일반적으로 여름철 주로 발생하는 해풍에 의해 고농도를 경험하게 되는데, 이는 해풍역전으로 인한 연직혼합의 억제와 (Lu and Turco, 1994) 해풍전선의 이동 (McElroy and Smith, 1991), 해풍의 내륙침투 시 생기는 Fumigation 효과(Entwistle, et al., 1997; Zhang et al., 1998) 등으로 설명되어 진다. 아울러 해륙풍순환으로 생기는 오전의 대기정체현상은 오후의 오존의 광화학 생성과 축적에 기여하게 되며 (Liu et al., 1994), 해풍 발달 시에는 오존 및 전구물질이 내륙 수송되어 풍하측 지역에 고농도가 나타나게 된다(Zhang et al., 1998). (중략)

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Preliminary Testing of an Urban Air Quality Model for Ozone Forecasting over the Sydney Basin (시드니만의 오존예측을 위한 도시대기질모델의 예비검사)

  • Speer, Milton S.;Leslie, Lance M.
    • Journal of Environmental Science International
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    • v.13 no.8
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    • pp.733-737
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    • 2004
  • FThe aim of this study was to carry out a preliminary test of the air quality modelling system (HIRES-AIRCHEM) developed at The University of New South Wales, particularly with regard to the forecast ozone distribution. This was achieved by assimilating the New South Wales State Environment Protection Authority (EPA) emissions inventory, consisting of road and non-road sources, and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA's goal of 8pphm on several occasions. The model forecasts of ozone distribution verified well with the EPA's ozone readings. This result has important implications for possible future use of the system as a tool for routinely predicting and assessing air quality.

Numerical Simulation for Diffusion and Movement of Air Pollutants in Atmospheric Flow Coastal Urban Region (연안도시지역의 대기유동장에서 대기오염물질의 확산과 이동에 관한 수치모의)

  • 이화운;김유근
    • Journal of Environmental Science International
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    • v.6 no.5
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    • pp.437-449
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    • 1997
  • To predict diffusion and movement of k pollutants In coastal urban region a numerical simulation shouts be consider atmospheric flow field with land-sea breeze, mountain-valley wand and urban effects. In this study we used Lagrangian [article dispersion method In the atmospheric flow field of Pusan coastal region to depict diffusion and movement of the Pollutants emoted from particular sources and employed two grid system, one for large scale calculating region with the coarse mesh grid (CMG) and the other for the small region with the One mesh 914 (FMG). It was found that the dispersion pattern of the pollutants followed local circulation system in coastal urban area and wale air pollutants exhausted from Sasang moved Into Baekyang and Jang moutain, air pollutants from Janglim moved into Hwameong-dong region.

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A Numerical Experiments on the Atmospheric Circulation over a Complex terrain around Coastal Area. Part I : A Verification of Proprietyh of Local Circulation Model Using the Linear Theory (연안부근 복잡지형의 대기유동장 수치실험 I -선형이론을 이용한 국지순환모형의 타당성 검토-)

  • 이화운;김유근;정우식
    • Journal of Environmental Science International
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    • v.8 no.5
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    • pp.555-558
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    • 1999
  • A sea/land breeze circulation system and a regional scale circulation system are formed at a region which has complex terrain around coastal area and affect to the dispersion and advection of air pollutants. Therefore, it is important that atmospheric circulation model should be well designed for the simulation of regional dispersion of air pollutants. For this, Local Circulation Model, LCM which has an ability of high resolution is used. To verify the propriety of a LCM, we compared the simulation result of LCM with an exact solution of a linear theory over a simple topography. Since they presented almost the same value and pattern of a vertical velocity at the level of 1 km, we had a reliance of a LCM. For the prediction of dispersion and advection of air pollutants, the wind filed should be calculated with high accuracy. A numerical simulation using LCM will provide more accurate results over a complex terrain around coastal area.

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Chloride Diffusion Coefficient and Steel Corrosion Properties of Concrete containing Hydrotalcite-based Corrosion Inhibitor (하이드로탈사이트계 방청제를 혼입한 콘크리트의 염화물확산계수 및 철근부식특성)

  • Kang, In-Young;Kim, Gyu-Yong;Yoon, Min-Ho;Hwang, Eui-Chul;Seo, Won-Woo;Son, Min-Jae
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.90-91
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    • 2017
  • Concrete can be used semi-permanently unless the steel is corroded. However, the concrete exposed to the marine environment is exposed to sea breeze, so chloride ions penetrate into the concrete and the steel is corroded accordingly. In order to solve these problems, there is a method of increasing the covering depth of the concrete and an application of the epoxy paint to the steel. In this study, the hydrotalcite type corrosion inhibitor was mixed with the concrete and the compressive strength, chloride diffusion coefficient and the corrosion properties of the steel were examined.

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Local Wind Field Simulation over Coastal Areas Using Windprofiler Data (윈드프로파일러 자료를 이용한 연안 지역 국지 바람장 모의)

  • Kim, Min-Seong;Kim, Kwang-Ho;Kim, Park-Sa;Kang, Dong-Hwan;Kwon, Byung Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.2
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    • pp.195-204
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    • 2016
  • In this paper, the applicability and usefulness of windprofiler input data were investigated to generate three dimensional wind field. A logical diagnostic model CALMET with windprofiler data at ten sites and with weather forecasting model WRF output was evaluated by statistically comparing with the radiosonde data at eight sites. The horizontal wind speed from CALMET simulated with hourly windprofiler data is in good agreement with radiosonde observations within 1.5 m/s of the root mean square error, especially local circulation of wind such as sea breeze over the coastal region. The root mean square error of wind direction ranged $50^{\circ}{\sim}70^{\circ}$ is due to the wind direction error from the windprofiler polluted by ground clutters. Since the exact wind can be produced quickly and accurately in most of the altitude with windprofiler data on CALMET, we expect the method presented in this study to be useful for the monitoring of safe environment as well as weather in the coastal zone.

An Analysis on the Characteristics of Wind Distribution in the Coast of Busan Using AWS Data (AWS 데이터를 이용한 부산 해안의 바람분포 특성 해석)

  • Seol, Dong-Il
    • Journal of Navigation and Port Research
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    • v.33 no.8
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    • pp.549-554
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    • 2009
  • Wind velocity and wind direction are very important in the viewpoint of ship's safety and stability of port structure. The characteristics of wind distribution in the coast of Busan are analyzed for 10 years from 1997 to 2006 using AWS(Automatic Weather System) data. The characteristics of wind distribution of Miryang, is not affected by the land and sea breeze are also examined to understand clearly the characteristics of wind distribution in the coast of Busan. The mean wind velocity in the coast of Busan is stronger than that of Miryang. The mean wind velocitie at Youngdo and Gadukdo stations of Busan are stronger about 2.0 times than those at IlGwang, Haeundae and Daeyeon stations. The correlation a states show that the variation tendencies of monthly mean wind velocitie in the coast of Busan are very similar. The maximum monthly mean velocitie in the coast of Busan are recorded in September. This re ult is closely related to the influence of typhoon. The maximum instantaneous wind velocitie are also strong at Youngdo and Gadukdo stations and the peaks of maximum instantaneous wind $velocit^9$ are observed mainly from August to September. In the coast of Busan, the SW'ly-NNE'ly wind are prevailing in the winter and the SW'ly and NE'ly wind are predomi snt in the spring. w that the vs of wind direction in the summer and athumn are similar with those in the spring and winter, respectively.

Analysis of Wave Parametric Characteristics using WAVEWATCH-III Model and Observed Buoy Data (파랑모델과 부이 자료를 이용한 파랑인자 특성 분석)

  • 장유순;서장원;김태희;윤용훈
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.3
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    • pp.274-284
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    • 2003
  • The analysis of wave parametric characteristics in sea regions in the vicinity of Korean Peninsula have been carried out using the third generation wave model, WAVEWATCH-III (Tolman, 1999) and four observed buoy data of Korea Meteorological Administration (KMA). Significant wave height increases about 2-3 hours later after the increase of wind speed. Maximum correlation coefficient between two parameters appears in Donghae buoy data, which is at off-shore region. When land breeze occurs, it can be found that the correlation coefficient decreases. Time differences between wind speeds and wave heights correspond to significant tidal periods at all of the buoy locations except for Donghae buoy. After verifying the WAVEWATCH-III model results by the comparing with observed buoy data, we have carried out numerical experiments near the Kuroshio current and East Sea areas, and then reconfirmed that when there exist an opposite strong current in the propagation direction of the waves or wind direction, wave height and length get higher and shorter, respectively and vice versa. It has been shown that these modulations of wave parameters are considerable when wind speed is week or mean current is relatively strong, and corresponding values have been represented.

A Study on Changes in Local Meteorological Fields due to a Change in Land Use in the Lake Shihwa Region Using Synthetic Land Cover Data and High-Resolution Mesoscale Model (합성토지피복자료와 고해상도 중규모 모형을 이용한 시화호 지역의 토지이용 변화에 따른 주변 기상장 변화 연구)

  • Park, Seon Ki;Kim, Jee-Hee
    • Atmosphere
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    • v.21 no.4
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    • pp.405-414
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    • 2011
  • In this study, the influence of a change in land use on the local weather fields is investigated around the Lake Shihwa area using synthetic land cover data and a high-resolution mesoscale model - the Weather Research and Forecasting (WRF). The default land cover data generally used in the WRF is based on the land use category of the United States Geological Survey (USGS), which erroneously presents most land areas of the Korean Peninsula as savannas. To revise such a fault, a multi-temporal land cover data, provided by the Ministry of Environment of Korea, was employed to generate a land cover map of 2005 subject to the land use in Korea at that time. A new land cover map of 1989, before the construction of the Lake Shihwa, was made based on the 2005 map and the Landsat 4-5 TM satellite images of two years. Over the areas where the land use had been changed (e.g., from sea to wetlands, towns, etc.) due to the Lake Shihwa development project, the skin temperature decreased by up to $8^{\circ}C$ in the winter case while increased by as much as $14^{\circ}C$ in the summer case. Changes in the water vapor mixing ratio were mostly affected by advection and topography in both seasons, with considerable increase in the summer case due to continuous sea breeze. Local decrease in water vapor occurred over high land use change areas and/or over downstream of such areas where alteration in wind fields were induced by changes in skin temperature and surface roughness at the areas of land use changes. The albedo increased by about 0.1% in the regions where sea was converted into wetland. In the regions where urban areas were developed, such as Songdo New Town and Incheon International Airport, the albedo increased by up to 0.16%.