• Title/Summary/Keyword: bottom topography

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A Numerical Modeling Study on the Interannual Variability in the Gulf of Alaska (알라스카 만의 경년변화에 대한 수치모형 실험)

  • Bang, In-Kweon;Zygmunt Kowlik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.3
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    • pp.298-308
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    • 1994
  • Ocean circulation in the Northeast Pacific Ocean is simulated using a high-resolution primitive equation numerical model with realistic bottom topography. The goal is to explain better the details of observed interannual variability of the circulation in the Gulf of Alaska. Our numerical model suggests that there is no seasonal shift in the Alaska gyre and that the interannual variability. reported earlier, is most likely the result of embedded mesoscale eddies in the dynamic topography. Such eddies have been observed in hydrographic. satellite-tracked drifters and altimeter data from the Gulf of Alaska.

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Analysis of Bragg Reflection with Two-Dimensional Finite Element Method (2차원 유한요소법을 이용한 파랑의 Bragg반사 해석)

  • Cho, Yong-Sik;Jeong, Woo-Chng
    • Journal of Korea Water Resources Association
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    • v.35 no.6
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    • pp.677-684
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    • 2002
  • In this study, a finite element model is employed to simulate the diffraction of waves caused by a change of water depths. The model is firstly applied to the estimation of reflection coefficients of monochromatic waves over a sinusoidally varying topography. Predicted coefficients are compared with those of the eigenfunction expansion method and laboratory measurements. A good agreement is observed. The model is then used to investigate effects of heights of bottom topography and number of ripples on variation of reflection coefficients of monocromatic water waves.

Numerical experiments on the Tsushima Warm Current

  • Nam, Soo-Yong;Suk, Moon-Suk;Chang, Kyung-Il;Seung, Young-Ho
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1995.10a
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    • pp.16-19
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    • 1995
  • Effects of the changes in bottom topography and non-linearity of the western boundary current on the separation position of the Tsushima Warm Current(TWC) are investigated using a primitive equation model in a simplified model domain which consists of a deep ocean, a continental shelf and a marginal sea(Fig. 1). (omitted)

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SL/SST variations and their correlations in the North East Asian Sens by remote sensing (Topex/Poseidon, NOAA)

  • Yoon, Hong-Joo
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.297-299
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    • 2003
  • Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea(Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

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Development of Extended Boussinesq Equations over an Arbitrary Bottom Topography (임의의 수심 변화에 적용되는 확장형 Boussinesq 방정식 개발)

  • 이창훈
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.53-57
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    • 2003
  • 불규칙파를 사용하여 설계 자료로 이용하기 위해서는 설계해역에서 불규칙파의 파랑변형을 예측할 수 있는 수치모형의 개발이 선행되어야 한다. 비선형 불규칙파의 거동을 해석할 수 있는 Boussinesq 방정식은 상대파고인 $\alpha$/h($\alpha$는 수면의 진폭, h는 수심임)를 비선형의 매개변수로 하고 상대수심인 kh(k는 파수임)를 분산성의 매개변수로 하여 섭동법을 사용하여 유도된다. Boussinesq 식은 수심이 일정한 경우에 Boussinesq(1872)가 비선형 항을 O($\alpha$/h,(kh)$^2$)까지 포함하여 처음으로 개발하였고 수심의 변화가 완만한 경우에 Peregrine(1967)이 개발하였다. (중략)

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SL/SST variations and their Correlations in the North East Asian Seas by Remote Sensing

  • Yoon, Hong-Joo
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.58-60
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    • 2003
  • Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate. SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

ON HOMOGENEOUS SHEAR FLOWS WITH BOTTOM CROSS SECTION

  • S. LAVANYA;V. GANESH;G. VENKATA RAMANA REDDY
    • Journal of applied mathematics & informatics
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    • v.41 no.5
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    • pp.1071-1084
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    • 2023
  • We consider inviscid, incompressible homogeneous shear flows of variable cross section known as extended Rayleigh problem. For this extended Rayleigh problem, we derived instability region which intersect with semi-circle instability region under some condition. Also we derived condition for stability, upper bound for amplification factor and growth rate of an unstable mode.

On the Cold Water Mass Around the Southeast Coast of Korean Peninsula

  • An, Hui Soo
    • 한국해양학회지
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    • v.9 no.2
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    • pp.10-18
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    • 1974
  • The cold water mass around the southeast coast of the Korean Peninsula is analyzed by using CSK data from 1966 through 1970. It is shown that this water mass flows down from the region offshore of Jukbyun to the area of Youngil Bay along the 100meter contour line of bottom topography. In ordinary summer conditions when the current velocity in the Korea Strait is usually above about 50cm/sec and the wind direction is southwest, the cold water ascends to the surface and makes the surface temperature gradient large, unless disturbed by a tropical cyclon. The bottom water of the Korea Strait is formed by the stratification after the Tsushima intermediate water and the Japan Sea intermediate water have been mixed. In winter the Tsushima intermediate water with high salinity sinks rapidly around the inlet of the Japan Sea and prevents the Japan Sea intemediate water from entering the Korea Strait.

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Comparison between Variational Approximation and Eigenfunction Expansion Method for Wave Transformation over a Step Bottom (단일계단 지형에서 변분근사법과 고유함수 전개법에 의한 파랑변형 비교)

  • Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.2
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    • pp.91-107
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    • 2009
  • In order to compute linear wave transformation over a single step bottom, both variational approximation and eigenfunction expansion method are used. Both numerical results are in good agreement for reflection and transmission coefficients, surface displacement respectively. However x velocity profiles at the boundary of step are seen to be different to each other even though x velocity matching condition is used.