• Title/Summary/Keyword: M2조석

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Rapid Estimation Method of Tidal Predictions in Namhaedo Area (남해도 해역 조석의 신속 추정법)

  • 최병호;고진석;김동철
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.4
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    • pp.368-378
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    • 1995
  • Using two-dimensional depth-integrated tidal computation model. tidal charts of eight major tidal constituents (M$_2$, S$_2$, $K_2$, $N_2$, $K_1$, $O_1$, P$_1$, Q$_1$) are presented for Namhaedo area. Computed distributions of tides were compared with observations. Subsequently, the model was run for one month to derive harmonic constants of tides and tidal currents, thus for formulating predictive data tables. Data tables are then used as PC-based rapid estimation of tides in this area.

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Analysis of Tidal Asymmetry and Flood/Ebb Dominance around the Yeomha Channel in the Han River Estuary (한강하구 염하수로 주변에서의 조석·조류 비대칭과 창·낙조 우세 분석)

  • Yoon, Byung-Il;Woo, Seung-Buhm
    • Journal of Korea Water Resources Association
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    • v.45 no.9
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    • pp.915-928
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    • 2012
  • Han River estuary (HRE) is located at the middle of the western coast of Korea, and tidal currents were measured at 4 stations in this estuary during the winter season, and previously observed tide data was analyzed. The results of amplitude ratio of $M_4/M_2$ showed that increasing upward to estuary in the HRE. Tide harmonic constants of relative phase $2M_2-M_4$ represent flood dominance, with under 180 degree. But this method has a limit of analysis that typically based on the non-linear distortion of the tidal current in tidal lagoon system where freshwater discharge is assumed to be relatively small. The results of statistically tidal current data indicated that ebb current velocity would be great unlike tide data. Ebb and flood duration time is calculated by slack time of tidal current showed that ebb duration time is longer than flood. The results of correlation of analysis show high value (0.9) between tidal current stations from Incheon harbor to north entrance of Yeomha channel. We reconstructed to find the reasons for the features of ebb dominance the results of harmonic analysis. As major component ($M_2$) in combination with shallow water component ($M_4$), the tidal curve was presented flood dominance that has a flood current is stronger. However, these curve were changed to ebb dominance add up the non-harmonic components that had ebb direction flow by calculated tidally averaged current. The characteristic of enhancement on ebb is showed around the Yeomha channel in the HRE, because averaged flow which acts seaward such as long-term tidal current components due to non-linear effect and freshwater which overcome the flood current.

Modelling of Tides in the Bay of Bengal (벵갈만의 조석)

  • 최병호;고진석
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.3
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    • pp.290-297
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    • 1994
  • As satellite altimetry is being progressed to apply with higher precision to marginal seas, it is necessary to improve correction procedures fer tidal signals in altimetry with more accurate tidal model than the well-known model of Schwiderski. The Bay of Bengal renders many conspicuous coastal oceanographic issues including tide and storm surge interactions along the upper Bangladesh coast. As a first step. tidal regime of semidiurmal tides (M$_2$, S$_2$, $N_2$, $K_2$) and diurnal tides (K$_1$, $O_1$, P$_1$) are computed with a model having a mesh resolution of 1/4 degree over the whole Bay of Bengal. Computed results are discussed with observation and previous Schwideski's tidal map of the region.

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An Analytic Model of hte M$_{2}$ Tide near Cheju Island (濟州道 周邊 M$_{2}$潮에 대한 解析的 모델)

  • Kang, Yong Q
    • 한국해양학회지
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    • v.19 no.1
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    • pp.18-23
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    • 1984
  • The M$\sub$2/ tide near Cheju Island in studied on the bases of a scattering of incident tidal wave by an elliptic island in an ocean of constant depth. The amplitudes of incident and scattered waves are determined from the required boundary condition and by the least squares fit of the model to the tidal observations at 7 stations in the island. The tidal chart for M$\sub$2/ tide near the island is analytically constructed.

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Tidal asymmetry in the Keum River Estuary (금강하구의 비선형조석)

  • 최병호
    • Water for future
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    • v.21 no.1
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    • pp.87-94
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    • 1988
  • Tidal asymmetry in the Keum River Estuary has been investigated from the observed tides. Despite strong frictional attenuation within the estuary, the $M_4$ tides reach significant amplitude, resulting in strong tidal distortion. The observed asymmetry over the area shows that generally more intense flood flows transport more sediment that do less intense ebb flows of longer duration. This causes filling of the estaury as evidenced by sand flats spreaded over the inner area. The spatial distribution of peak bottom stress associated with the dominant $M_2$ and $M_4$ tides calculated via two-dimensional numerical tidal model suggest that present tidal sedimentation regimemay be altered, sepecially in the approach channel to outer Kunsan Port and downstream part of the dike, due to the construction of barrier.

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Numerical Simulation of Tides of Gwangyang Bay Using Moving Boundary Treatment (이동경계를 고려한 광양만의 조석ㆍ조류 모의)

  • 민인기;오병철;전인식
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.158-163
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    • 2003
  • 한반도 서ㆍ남해안은 크고 작은 만과 해빈, 삼각주, 하구, 조간대 등 다양한 연안해역이 잘 발달 되어 있다 평균조차는 서해안 남부에서 약 3m로 북쪽으로 갈수록 증가하여 군산 부근에 6m, 인천 부근에서 약 8m에 달하며, 남해안의 평균조차는 부산 1.2m, 진해 2.1m, 충무 2.6m, 삼천포 3.0m, 여수 3.3m, 완도 3.5m, 목포 3.7m로 조석 간만의 차가 크게 나타나서 연안해역에 폭넓은 조간대가 형성되어 있다. (중략)

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Estimation of Extreme Tide for Risk Analysis of Marine Salvage in the Namhae (southern sea of Korea) (한국 남해의 구난환경 위험성 분석을 위한 극치 조석 산정)

  • Lee Moon-Jin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.33-38
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    • 2006
  • In marine salvage, extreme tide heights and tidal currents are necessary to anchor an accidental ship. In order to meet this requirement, a simple scheme was developed which yields the spatial informations on the extreme tide from the distribution of approximate highest astronomical tide heights using a relationship between extreme and highest astronomical tides at the standard port. This method is the inference method based on horizontally homogeneity of tide. This scheme was applied to estimate extreme tide heights and tidal currents in the Namhae (southern sea of Korea). The highest astronomical tide heights are computed by amplitude of four major constituents (M2, S2, K1, O1 tide). The estimated extreme tide heights are ranged from 70 to 260 cm for return period 50 years and from 80 to 270cm for return period 100 years, respectively. For return period 100 years, extreme tidal currents show value of 1.55 times as strong as those of normal state.

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A Tidal Model of the Arabian Gulf (아라비아만(灣)의 조석(潮汐)모델)

  • Choi, Byung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.2
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    • pp.67-76
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    • 1988
  • A fully non-linear two-dimensional model for studying basic tidal dynamics within the Arabian Gulf has been formulated. The model extends to the east as far as continental shelf edge and has a mesh resolution of 1/12 degree latitude by 1/10 degree longitude. The developed model was used to investigate the distribution of dominant $M_2$, $S_2$, $K_1$, $O_1$ and $N_2$ tides adopting the open boundary tidal information from Schwiderski's global ocean tidal model. Computed co amplitude and cophase charts were presented independently and comparison between these charts and existing Admiralty tidal charts were made. Maximum bottom stress vector during the semidiurnal period due to $M_2$ and $M_4$ tides are also presented to suggest the possible direction of sediment movement in the region.

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Tidal Computation of the Global Ocean using Fine-grid Numerical Model (세격자체계에 의한 전지구 해양 조석 산정)

  • 최병호;서경석
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.15 no.1
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    • pp.51-61
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    • 1997
  • A two-dimensional numerical tidal model with $1/3^\circ$ resolution has been established to investigate the distribution of semidiurnal constituents$(M_2,\;S_2,\;K_2,\;N_2)$ and diurnal constituents$(K_1,\;O_1,\;P_1,\;Q_1)$ of the global ocean. The $1/3^\circ$ numerical model has been applied to the computation of detailed tidal distributions in the marginal seas and the shelf seas. Tidal characteristics in shallow areas could be hardly resolved with the existing global chart due to the low resolution. Computed tidal charts obtained by $1/3^\circ$ numerical model have been compared with the existing global charts and the altimetry-derived tidal charts. Computed harmonic constants have also been com-pared with the pelagic tidal observations. The results obtained with fine-grid numerical model can be used to determine the time-independent sea surface topography by removing the tidal components from the altimetry-derived sea surface height.

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Effect of Nonlinear Terms on the Generation of $M_2$ Tide Residual Elevation and $M_4$ Tide in the Yellow Sea and the East China Sea (황해ㆍ동중국해의 $M_2$ 조석 잔차위 및 $M_4$ 조석 생성에 대한 비선형항의 영향)

  • 이종찬;정경태;최병호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.2
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    • pp.137-145
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    • 1996
  • Effects of nonlinear terms on the generation of M$_2$ tide residual elevation and M$_4$ tide in the Yellow Sea and the East China Sea are investigated using a depth-integrated two-dimensional nonlinear M$_2$tidal model. The model domain (117$^{\circ}$E-130$^{\circ}$E, 24$^{\circ}$N-41$^{\circ}$N) covers the whole region of the Yellow Sea and the East China Sea with grid resolution of 1/6$^{\circ}$ in longitude and 1/8$^{\circ}$in latitude. A radiational boundary condition is used along the open boundaries. Calculations show that advection terms yield negative residual elevation, while shallow-water terms in continuity equation yield positive residual elevation. The contribution of both advection terms and shallow-water terms to tile generation of the M$_4$ constituent is more than 90 percents, but that of quadratic bottom friction terms to the M$_4$ constituent is comparatively small.

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