• Title/Summary/Keyword: Sea-and-air

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Numerical Simulation for Recirculation of Air Mass in the Coastal Region Using Lagrangian Particle Dispersion Model (라그랑지안 입자확산모델을 이용한 광양만 권역에서의 공기괴 재순환현상 수치모의)

  • Lee, Hwa-Woon;Lee, Hyun-Mi;Lee, Soon-Hwan;Choi, Hyun-Jung
    • Journal of Environmental Science International
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    • v.19 no.2
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    • pp.157-170
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    • 2010
  • Air mass recirculation is a common characteristic in the coastal area as a result of the land-sea breeze circulation. This study simulates the recirculation of air mass over the Gwangyang Bay using WRF-FLEXPART and offers a basic information about the effective domain size that can reflect recirculation. For this purpose, WRF is set up four nested domains and three cases are selected. Subsequently FLEXPART is operated on the basis of WRF output. During the clear summer days with weak wind speed, particles that emitted from Yeosu national industrial complex and Gwangyang iron works flow into emission sources because of the land-sea breeze. When land-sea breeze is strengthen, the recirculation phenomena appears clearly. However particles aren't recirculated under weak synoptic condition. Also plume trajectory is analyzed and as a consequence, the smallest domain area have to be multiplied by 1.3 to understand recirculated dispersion pattern of particles.

An Analysis of the Case related with High PM10 Concentrations Using a Fine Grid Air Dispersion Modeling in Ansan Area (미세 격자 대기 확산 모델링을 통한 안산지역 PM10 고농도 사례 분석)

  • 송동웅;송창근
    • Journal of Environmental Science International
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    • v.12 no.9
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    • pp.977-986
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    • 2003
  • In this study, the scenario for a numerical modeling of the fine grid scale air dispersion phenomena was proposed and an analysis of the special event which was occurred on September 3, 2002 was performed using by a coarse grid prognostic meteorological model, a fine grid diagnostic meteorological model and a fine grid air dispersion model. Based on the results, we found that the local circulations, like as land-sea breeze, should be seriously considered for evaluating the high PM10 concentration event and for making the reduction policy of the major air pollutant emissions in Ansan area.

A Study on the Dispersion of Air Pollutants in Local Circulation of Mesoscale (중규모 국지 순환에서 대기 오염 물질의 확산에 관한 연구)

  • 이화운;오은주
    • Journal of Environmental Science International
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    • v.3 no.1
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    • pp.39-47
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    • 1994
  • Dispersion characteristics of air pollutants in the mountainous coastal area are investigated in considering with the mesoscale local circulations using a two dimensional numerical model with two kinds of topograpy of 500m and 300m. In the model, land-sea breezes and mountain-valley wind are mainly considered under the condition of the absence of large scale prevailing flow in the circulation analysis, and the pollutants dispersion is traced by the Lagrangian methods. According to the results, the wind velocity is affected by topography and is stronger in the case of 500m height mountain than that of 300m, the Pollutants that source is near the coast transported over the mountain and dispersed to behind inland area. It is classified that the topography change control affects the wind velocity and the circulations. The pollutants that source is different transported and concentrated to behind inland and/or diffused to the sea area by the combination of the wind system with topographic changes. The results can be applied to the air pollution control with the arrangement design of industrial area and the planning of coastal developments.

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Improvement of GPS PWV retrieval capability using the reverse sea level corrections of air-pressure (기압의 역해면 경정 보정을 이용한 GPS PWV 복원 능력 개선)

  • Song, Dong-Seob
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.5
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    • pp.535-544
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    • 2009
  • Signals from the Global Positioning System(GPS) satellite are used to retrieve the integrated amount of water vapor or the precipitable water vapor(PWV) along the path between a transmitting satellite and ground-based receiver. In order to retrieve the PWV from GPS signal delay in the troposphere, the actual zenith wet delay, which can be derived by extracting the zenith total delay and subtracting the actual zenith hydrostatic delay computed using surface pressure observing, will be needed. Since it has been not co-located between GPS permanent station and automated weather station, the air-pressure on the mean sea level has been used to determine the actual zenith hydrostatic delay. The directly use of this air-pressure has been caused the dilution of precision on GPS PWV retrieval. In this study, Korean reverse sea level correction method of air-pressure was suggested for the improving of GPS PWV retrieval capability and the accuracy of water vapor estimated by GPS was evaluated through a comparison with radiosonde PWV.

A Study on a development plan for multi-transportation in Incheon: Focused on Incheon and main cities in Northern China (인천지역의 복합운송체계별 발전방안 연구 - 인천과 상해이북지역 중심으로 -)

  • Chung, Tae-Won
    • Journal of Korea Port Economic Association
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    • v.26 no.1
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    • pp.259-276
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    • 2010
  • This study shows how Incheon will advance into roadmap as multi-transport hub in Northeast Asia hereafter and be proposed an urgent tasks and roles to construct a multi-transportation system for Incheon, which has both an international airport and port. The multi-transportation point of view of inter-major cities competitiveness of total scores was proposed 1. Shanghai(64.8 points), 2 in Hongkong(64.5), 3 in Incheon(62.9), and 4 in Busan(60.4) and Incheon was estimated to have enough competitiveness to be the international multi-transport hub in Northeast Asia. Sea & Air transportation revealed the most important multi-transportation in the Incheon region. In conclusion, this research suggests a development plan for multi-transportation in Incheon. Firstly, it proposes construction of sea & air transportation distribution center and agreement that simplifies logistic process between Incheon and Tianjin, secondly, suggests to activate project for the purpose of creating a better sea-land transportation system between Incheon and Shanghai.

Characteristics of Spatio-temporal Variability of Daily averaged Tidal Residuals in Korean Coasts (한국연안 일평균 조위편차의 시공간적 변동 특성)

  • Kim, Ho-Kyun;Kim, Young-Taeg
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.6
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    • pp.561-569
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    • 2013
  • EOF analysis of tidal residual derived from 2003~2009 tide data was used to identify the spatio-temporal variability. The effect of sea surface air pressures and winds on the tidal residual was also investigated by the correlation analysis. The first mode accounting for 68 % of the total variance represented concurrent sea level rise or fall, and the second mode accounting for 21 % of the total variance explained alternative sea level rise and fall between West Sea coast and both South Sea and East Sea coasts. While northerly and southerly winds dominated the tidal residual in the eastern coast of Yellow Sea, the effect of sea surface air pressures on the tidal residual increased along the coastal regions from South Sea to East Sea.

A Study on Prediction System of Sea Fogs in the East Sea (동해의 해무 예측 시스템 연구)

  • 서장원;오희진;안중배;윤용훈
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.2
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    • pp.121-131
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    • 2003
  • We have found that the east coast of Korea has had few sea fogs on January, February, November and December for the past 20 years by the analysis of monthly fog frequency and duration time. These phenomena appear to relate to the topographical characteristics of which the Taebaek Mountains descends toward the east to bar the radiation fog. On the other hand, the cause of occurring the spring and summer fog which has 90% of the whole frequency is divided into three cases. The first is the steam fog caused by the advection of the northeast cold air current on the East Sea due to the extension of Okhotsk High. The second is the advection fog caused by cooling and saturation of warm airmass advected on cold sea surface. And the last is the frontal fog caused by the supply of enough vapor due to the movement of low-pressure system and the advection of cold air behind a cold front. While, we simulate the sea fog for the period of the case studies by implementing fog prediction system(DUT-METRI) that makes it possible to forecast the fog in the vertical section of neighborhood of the East Sea and to predict the sea surface wind, relative humidity, ceiling height, visibility etc. Finally we verified this result by satellite image.

Numerical Simulation of NOx Concentration in Gwangyang Bay, Korea (광양만권 질소산화물(NOx)의 수치모의)

  • 이상득;유지영
    • Journal of Environmental Science International
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    • v.11 no.9
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    • pp.897-905
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    • 2002
  • A three-dimensional photochemical air pollution model considered advection, dispersion, photochemical reactions, and precipitation processes was developed. The calculated results of meteorological observation clearly exhibited geographical effects of Gwangyang Bay, in which land and sea breezes, mount-valley winds and local circular winds occurred. The observed results of daytime NOx concentrations were slightly higher than the calculated NOx concentrations in Yosu industrial complex, Gwangyang iron mill, and container yard. Eventually, the calculated NOx results generally agreed well with the observed ones.

The Influences of Concentration Distribution and Movement of Air Pollutants by Sea Breeze and Mist around Onsan Industrial Complex (온산공업단지 주변의 박무와 해풍발생이 대기오염물질의 이동 및 농도분포에 미치는 영향)

  • Lee, Hyung-Don;Lee, Gou-Hong;Kim, In-Deuk;Kang, Ji-Soon;Oh, Kwang-Joong
    • Clean Technology
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    • v.19 no.2
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    • pp.95-104
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    • 2013
  • Onsan Industrial Complex located in a nearby the Ulsan Petrochemical Complex and in the east of the coast. For this reason, air pollution substances emitted by Onsan Industrial Complex especially tend to have an effect on meteorological factors such as sea breeze. In this study, we assessed the frequency of sea breeze and mist using the meteorological data, and analyzed potential temperature and upper wind condition for assessment of atmospheric pollution concentration influenced by meteorological phenomena in a nearby the Onsan industrial complex. From an analysis results, when mist and sea breeze happened, each higher concentration phenomenon of $PM_{10}$ and $SO_2$ appeared each 57.2%, 71.8% and 46.6%, 57.7% respectively. Hence, we confirmed that meteorological phenomena such as mist and sea breeze had an effect on high concentration of air pollution substances in the research area. Analytical result of meteorological data in upper layer using potential temperature and wind condition, we confirmed that advection of air pollution substances emitted in Ulsan Petrochemical Complex by sea breeze have an effect on high concentration in Onsan Industrial Complex and nearby the residential area. In particular;concentration in Onsan Industrial Complex were higher than the average concentration by a factor of more than over 1.5 times when sea breeze by stable condition in atmospheric layer appeared.