• Title/Summary/Keyword: wind circulation

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Development of Oceanic General Circulation Model for Climate Change Prediction (기후변화예측을 위한 해양대순환모형의 개발)

  • Ahn, Joong-Bae;Lee, Hyo-Shin
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.3 no.1
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    • pp.16-24
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    • 1998
  • In this study, Ocean General Circulation Model (OGCM) has been developed as a counterpart of Atmospheric General Circulation (AGCM) for the study of coupled ocean-atmosphere climate system. The oceanic responses to given atmospheric boundary conditions have been investigated using the OGCM. In an integration carried out over 100 simulated years with climatological monthly mean data (EXP 1), most parts of the model reached a quasi-equilibrium climate reproducing many of the observed large-scale oceanic features remarkably well. Some observed narrow currents, however, such as North Equatorial Counter Current, were inevitably distorted due to the model's relatively coarse resolution. The seasonal changes in sea ice cover over the southern oceans around Antarctica were also simulated. In an experiment (EXP 2) under boundary condition of 10-year monthly data (1982-1991) from NCEP/NCAR Reanalysis Project model properly reproduced major oceanic changes during the period, including El Ni$\tilde{n}$os of 1982-1983 and 1986-87. During the ENSO periods, the experiment showed eastward expansion of warm surface waters and a negative vertical velocity anomalies along' the equator in response to expansion of westerly current velocity anomalies as westerly wind anomalies propagated eastward. Simulated anomalous distribution and the time behavior in response to El Ni$\tilde{n}$o events is consistent with that of the observations. These experiments showed that the model has an ability to reproduce major mean and anomalous oceanic features and can be effectively used for the study of ocean-atmosphere coupling system.

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Robust Diagnostic World Ocean Circulation with Half-Degree Resolution (1/2$^{\circ}$해상도의 진단적 전구 해수순환모형 연구)

  • 최병호;웨이체첸;팡구오홍;최영진
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.1
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    • pp.80-87
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    • 2001
  • Global robust diagnostic models are established based on MOM of GFDL to study the circulation in the world ocean. The horizontal grid sizes 1/2 degree, and the vertical water column is divided into 21 levels. The hydrographic data are taken from Levitus et al.(1994) and the wind stress from Hellerman and Rosenstein (1983). Based on the model results the horizontal volume, heat and salt transports across some representative sections are calculated. The preliminary results show that Though the cross-equator volume transports in the Atlantic, Indian and Pacific Oceans are all small, the heat transports across equator in the Atlantic are northward. This is clearly a result of the southward flow of the North Atlantic Deep Water and the northward compensating warm flow in the upper layer. The annual mean of the cross-equator heat transport in the Pacific Ocean from the present model is significantly lower than that calculated by Philander et at. (1987). This might indicate the importance of the Indonesian Throughflow in the heat transport in the Pacific Ocean. Our calculation shows that the heat transport through the Indonesian Archipelago is 0.5 PW, which is comparable with the poleward heat transport in the North Atlantic and Pacific Oceans. The difference in heat transports across the sections 5 and 6 demonstrates the important role of the Agulhas Current in the heat balance of the world ocean.

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Observational Characteristics of East Asian Monsoon during the Summers of 1993 and 1994 (1993, 1994년 여름철 동아시아몬순의 관측 특성)

  • Kim, Baek-Jo;Ryu, Chan-Su
    • Journal of the Korean earth science society
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    • v.23 no.4
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    • pp.369-379
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    • 2002
  • The characteristics of the East Asian summer monsoon circulation associated with the cool and wet summer of 1993 and the warm and dry summer of 1994 are investigated by analyzing the atmospheric circulations features in the upper and lower troposphere and by examining the global SST and associated tropical convective precipitation fields. The negative geopotential height anomalies at 500 hPa and 200 hPa in 1993 over East Asia, the central North Pacific, and the western United States were replaced by positive ones in 1994. In addition, the 200 hPa zonal wind anomaly averaged over the East Asian summer monsoon region is negatively correlated with the Korean summer temperature anomaly. The subtropical jet stream in 1993 was displaced into the central part of Korea well south of its normal position. The western Pacific subtropical high was shifted southward, and the East Asian summer rainfall and temperature was above-normal and below-normal, respectively due to the southwestward extension of a cold and dry polar airmass from the Sea of Okhotsk to the Est Sea. In contrast, the subtropical jet stream in 1994 was displaced well north of its normal position. The abrupt northward shift of the western Pacific subtropical high was accompanied with the rapid northward movement of the rain band of the East Asian summer monsoon rainfall. The anomaly patterns of the East Asia summer rainfall and temperature were opposite to those of 1993. Large sea surface temperature anomalies of opposite signs existed in the tropical Pacific with a mature El $Ni{\~{n}o$ in 1993 and a weak La $Ni{\~{n}a$ condition in 1994. The role of the anomalous convective precipitation in the western Pacific and the Indian Ocean related with the variations in the low-level cross-equatorial flow along the northwestern periphery of the Australian high and the Mascarene high is probably to influence a large-scale atmospheric circulation over the East Asia during both the years.

Simulation of Circulation and Water Qualities on a Partly Opened Estuarine Lake Through Sluice Gate (배수갑문을 통해 부분 개방된 하구호에서의 순환과 수질모의)

  • 서승원;김정훈;유시흥
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.2
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    • pp.136-150
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    • 2002
  • To improve the water quality of the recently constructed Siwhaho, sluice gates were operated to allow free exchange of water with the sea. This estuarine lake connected to the outer sea through narrow gates is affected mainly by flushing by gate operation and river flows and wind forcing sometimes. As a predicting tool far the water qualities, a three-dimensional finite volume model CE-QUAL-ICM is incorporated into a finite element hydrodynamic model, TIDE3D. In coupling these two different modules, a new error minimization technique is applied by considering conservation of mass. Model tests for one year after calibration and validation using field observation show that eutrophication and other biological changes reach quasi-steady state after initial 60 days of simulation, thus it would be necessary to consider moderate ramp up option to remove initial uncertainties due to cold start option. Sediment-water interaction might not be a concern in the long-term simulation, since its effect is negligible. Simulated results show the newly applied scheme can be applied with satisfaction not only fur lessening of eutrophic processes in an estuarine lake but also looking for some active circulation to improve water quality.

Numerical Simulation of Spilled Oil Dispersion in Taean Coastal Zone (태안유류유출사고의 유출유 초기확산 수치모의)

  • Jung, Tae-Sung
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.4
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    • pp.264-272
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    • 2009
  • Due to an oil spill accident occurred in Taean coastal zone wide range of coastal waters were polluted. Inaccurate prediction of spilled oil trajectory is known as a cause that has increased the pollution damage in the beginning stage. In this study, a numerical modeling of spilled oil dispersion has been conducted to know which physical factors caused the severe and wide pollution. Especially the simulation is focused on how to model hydrodynamic circulation accurately. The simulation results showed that the hydrodynamic flow is very important in predicting oil fate, specially, in the short-term dispersion of spilled oil.

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Multi-Dimensional Hybrid Design and Construction of Skyscraper Cluster -Innovative Engineering of Raffles City Chongqing-

  • Wang, Aaron J.
    • International Journal of High-Rise Buildings
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    • v.6 no.3
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    • pp.261-269
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    • 2017
  • Designed by star architect of Moshes Safdie, Raffles City Chongqing includes a total of 6 mega high-rise towers 250 to 380 m tall, a sky conservatory, a 5-storey high shopping mall and a 3-storey basement car parking. Located at the confluence of the Yangtze and Jailing Rivers, the site for the project is imbued with a significance that is immediately symbolic, both as a sign of Chongqing's important past and as a vivid indicator of the city's thriving present and future. The design for the project to be situated at this gateway takes as its governing idea the image of powerful sails upon the water. The outer facades of the project's eight towers - the transparent surfaces that will face the water to the north - are meant to recall a fleet of ancient Chinese ships, with their huge rectangles of white canvas filled by the wind. This is a $1.13million\;m^2$ mega scale integrated project of office, retail, hotel, service residence and high-end residence with the transportation hub and traffic circulation at various levels of the project. This paper presents the multi-dimensional hybrid design, engineering and construction of this mega scale project. The innovations and the cutting-edge technology used in this project are introduced and discussed benchmarking the design and construction of the skyscraper cluster in a major city like Chongqing of China.

Effect of Recirculated Exhaust Gas upon Performance and Exhaust Emissions in Power Plant Boilers with FGR System (FGR 시스템 공력 플랜트 보일러의 성능 및 배기 배출물에 미치는 재순환 배기의 영향)

  • Bae, Myung-Whan;Jung, Kwong-Ho;Choi, Seung-Chul;Cho, Yong-Soo;Kim, Yi-Suk
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1686-1691
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    • 2004
  • The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air(OFA) damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing $NO_{x}$ emissions. To activate the combustion, the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between $0^{\circ}$ and $90^{\circ}$ , and the OFA with 0 to 20% into the flame is supplied, as the combustion air supplied to burner is reduced. It is found that the fuel consumption rate divided by evaporation rate does not show an obvious tendency to increase or decrease with rising the FOR rate, and $NO_{x}$ emissions are decreased, at the same OF A damper opening, as FOR rates are elevated and boiler loads are dropped.

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전신성홍반성낭창(全身性紅斑性狼瘡)의 동의병리(東醫病理) 및 치법(治法)에 관(關)한 고찰(考察)

  • Lee, Seok-U;Kim, Han-Seong;Kim, Seong-Hun
    • The Journal of Korean Medicine
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    • v.16 no.1 s.29
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    • pp.51-70
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    • 1995
  • To find the cause, pathology, oriental presciptions for SLE(systemic lupus erythematous) in the field of oriental medicine, we studied the clinical reports. The results were obtained as follows: 1. SLE can' be thought to be a category of chronic fatigue, numbness, yang poison' & erythema. 2. The chief cause of SLE could be a febrile poison and the lack of physiological fluid and the mechanism was that febrile poison attacted area of circulation and blood and injuried the physiological fluid to arise edema and clotted blood. 3. The therapy of SLE was chiefly clarifying heat and toxiciding in acute stage while reinforcing kidney and liver and supplementing Yin & clarifying in chronic stage, sometimes supplementing Qi, eliminating clotted blood, excuding wind and draining water could be applied. 4. The therapy for SLE nephritis was shown to be increasing yin and clarifying heat with toxiciding, reinforcing spleen and kidney, draining water, supplementing yin & Qi etc. The chief prescriptions were Seogakjihwangtang(犀角地黃湯), Wookakjihwangtang(牛角地黃湯), yeechihwan(二至丸), Daepowonjeon(大補元煎), Daepoeumhwan(大補陰煎), Kikukjihwangtang(杞菊地黃湯), Yookmijihwangtang(六味地黃湯) which indicates Rhemanniae radix added prescrition could be used chiefly for the treatment of SLE.

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Circulation in the Central South Sea of Korea in Spring 1999

  • Lee, Jae-Chul;Lee, Sang-Ho;Kim, Dae-Hyun;Son, Yong-Tae;Perkins, Henry-T.;Kim, Jeong-Chang;Pang, Ig-Chan
    • Journal of the korean society of oceanography
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    • v.38 no.3
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    • pp.143-155
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    • 2003
  • Current and sea level were observed in spring 1999 by a bottom mounted ADCP and tide gauge in the central part of the South Sea of Korea. With respect to the front, the distribution of isotherms is prograde in the offshore region whereas that of isohalines is retrograde, especially in the coastal area. The combined effect results in shoaling of isopycnals at the front. This distribution corresponds to a westward coastal flow on the northern side of the front and the eastward Tsushima Warm Current (TWC) to the south, determined by vessel-mounted ADCP observations. The low-frequency current shows either alternating clockwise-counterclockwise rotation or else persistent eastward motion depending on the frontal motion. Fluctuations of wind, sea level and current are coherent at period of 3-4 days and show some characteristics of Ekman-like dynamics.

Establishment of Ecological Environment Plan Item on Urban Development Stages (도시개발 사업 단계별 생태환경계획수립 항목 설정에 관한 연구)

  • Lee, Eun Yeob;Kang, Myung Su
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.4
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    • pp.12-23
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    • 2008
  • This study has a purpose of setting applicable ecological environment plan items when establishing city development plan. To achieve this purpose, multiple methods of data gathering, documentary surveys, and questionaries research were used in this study. The main findings of this study can be summarized as follows; 1. The appliance of ecological environment plan is appropriate to apply before the establishment of development plan. 2. The items applicable to ecological environment plan establishment step by step is the following. First, it is necessary to prepare the environment improvement plan and ecology restoration on the stage of assigning the area. Second, on the stage of planning development plan, it is required to set the restoration plan of ecological resources and step by step ecological environment plan. Third, on the stage of plan implementation, it is required to set the maintenance guide on ecological environment. 3. The planning items of ecological environment plan are "geographical features and soil", "water resource", "wind resource", "green resource", "circulation of resource", "usage of nature energy" and "habitats", etc. 4. To apply ecological environment plan to the planning of development, it is necessary to specify the clear concepts and specific plan. 5. This study is limited to select generalized planning items and later on, it is necessary to develop detailed planning contents.