• Title/Summary/Keyword: ocean tide

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Relative Sea-level Change Around the Korean Peninsula

  • Jeon, Dong-Chull
    • Ocean and Polar Research
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    • v.30 no.4
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    • pp.373-378
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    • 2008
  • Long-term tide-gauge data from around the Korean Peninsula were reanalyzed. Both the coastal water and the open sea surrounding the Korean Peninsula appeared to have been influenced by global warming. The long-term change in relative sea levels obtained from tidal stations showed a general rising trend, especially near Jeju Island. It is proposed that global warming may have caused shifting of the path of the Kuroshio branch (Tsushima Warm Current) toward Jeju Island, causing a persistent increase in the water levels along the coast of the island over the last few decades.

Trend of Utilization Techniques of Ocean Energy in Korea : Tide and Tidal Current Energy (국내 해양에너지 실용화 동향: 조력, 조류에너지)

  • Cho, Dae-Hwan;Yang, Chang-Jo;Choi, Min-Sun;Choi, Ju-Yeol
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.257-258
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    • 2006
  • 해양에너지는 지구의 70%를 점유하는 해양이 태양에너지를 받아서 그것을 내부 에너지로 저장하는 것으로 지속적 보급을 받고 있는 재생 가능한 에너지이다. 본 논문은 해양에너지를 실용화 하는 연구개발 분야 중 최근 주목받고 있는 조력 및 조류에너지에 대해 국내의 동향을 소개하고자 한다.

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Tide and Tidal Currents in the Tusima Strait, and the Japan Sea Tides

  • Odamaki, Minoru
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1992.08a
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    • pp.1-4
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    • 1992
  • New cotidal charts of the Tusima Strait has been edited by ODAMAKI (1989a) using tidal current observation data. For the semidiurnal tide as shown in Fig.1, two distinctive features are detected. One is an anti-amphidromic area located in the south coast of Korea. Another is the amplitude gap between west and east coasts of the Tusima.(omitted)

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Effects of Red-Tide and Toxic Dinoflagellates on the Survival and Growth of Larvae of the Mussel, Mytilus galloprovincialis

  • Lee, Chang-Hoon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.05a
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    • pp.373-374
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    • 2003
  • There were many studies on the effects of red tide dinoflagellates on shellfish populations (Nielsen and Stromgren, 1991; Lesser and Shumway, 1993; Luckenbach et al., 1993; Matsuyama et al., 1997; Li et al., 2001). However, these studies mainly focused on the toxic effects of dinoflagellates oui adults or juveniles. Interactions between dinoflagellates and bivalve larvae have not been understood comprehensively yet. (omitted)

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Monitoring suspended sediment distribution using Landsat TM/ETM+ data in coastal waters of Seamangeum, Korea

  • Min Jee-Eun;Ryu Joo-Hyung;P Shanmugam;Ahn Yu-Hwan;Lee Kyu-Sung
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.340-343
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    • 2004
  • Since the tide embankment construction started in 1991, the coastal environment in and around the Saemangeum area has undergone changes rapidly, there is a need for monitoring the environmental change in this region. Owing to high temporal and spatial heterogeneity of the coastal ecosystem and processes as well as the expense with traditional filed sampling at discrete locations, satellite remote sensing measurements offer a unique perspective on mapping a large region simultaneously because of the synoptic and repeat coverage and that quantitative algorithms used for estimating constituents' concentration in the coastal environments. Thus, the main objectives of the present study are to analyze the retrieved Suspended Sediment (SS) pattern to predict changes after the commencement of the tide embankment construction work in 1991. This is accomplished with a series of the Landsat TM/ETM+ imagery acquired from 1985-2002 (a total of 18 imageries). Instead of a simple empirical algorithm, we implement an analytical SS algorithm, developed by Ahn et al. (2003), which is especially developed for estimating SS concentration (SSC) in Case-2 waters. The results show that there is a significant change in SS pattern, which is mainly influenced by the tide and tidal height after the construction of the embankment work. As the construction progressed, the distribution pattern of SS has greatly changed, and the rate of SS concentration in the gap area of the dyke of post-construction has significantly increased.

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Initial Design of Offshore Floating Marina System (해상 부유식 마리나의 초기설계)

  • Chung H.;Oh T. W.;Namgoong S.;Kim S. B.;Jo C. H.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.11a
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    • pp.108-113
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    • 2004
  • Marinas are often located in prime port side locations. hi Korea these locations are already developed and reclamation of the existing properties poses many difficulties and financial overhead. Also, to develop a standard marina in Korea with tide ranges up to 6 meters would require considerable dredging and reclamation works needing long lead times and large SOC costs. The Ocean Space's floating marina system is an independent offshore floating static level system that does not require fixed location breakwaters. The entire marina floats with the tide giving a calm consistent berthing condition for vessels irrespective of the surrounding tide and weather conditions. The floating marina system provides also for all of functions needed to marina comprising a breakwater to protect the vessels, the pontoon system to house the vessels, a dub house and retail tourism precinct, fuel reservoir and associated support facilities in a turn key self contained unit. The modular nature of the system will mean that initial demand can be met with simple units and then further modules can be added quite easily without the related expansion difficulties or infrastructure. This paper contains the main characteristics of the floating marina system and tire design process of the structure. The mooring, motion & stability analysis, the overall & local structural design and the mooring & anchor system design are introduced in this paper.

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A Study on Possibility of Red Tide Detection Using MODIS Data (MODIS Data를 이용한 GOCI의 적조 탐지 가능성에 대한 연구)

  • Kim, Yong-Min;Byun, Young-Gi;Song, Woo-Seok;Yu, Ki-Yun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.131-134
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    • 2007
  • In this paper, we evaluate a red tide detection possibility of GOCI(Geostationary Ocean Color Imager) which will be launched in 2008. To detect red tide, we use a similar wavelength range of MODIS normalized water-leaving radiance data instead of GOCI data. Supposed to GOCI, red tide detection algorithm is based on MRI(MODIS Red tide Index) and use 667nm band to filter turbid water. The algorithm's effectiveness is verified by detecting large Cochlodinium polykrikoides red tide event that was appeared in Korean coastal waters. The evaluation was done by comparing the result with the update data provided by the NFRDI.

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Transoceanic Propagation of 2011 East Japan Earthquake Tsunami

  • Choi, Byung Ho;Kim, Kyeong Ok;Min, Byung Il;Pelinovsky, Efim
    • Ocean and Polar Research
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    • v.36 no.3
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    • pp.225-234
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    • 2014
  • The 2011 Tohoku earthquake triggered extremely destructive tsunami waves which propagated over the Pacific Ocean, Atlantic Ocean through Drake Passage and Indian Ocean respectively. A total of 10 tide-gauge records collected from the UNESCO/IOC site were analyzed through a band-pass digital filtering device to examine the observed tsunami characteristics. The ray tracing method and finite-difference model with GEBCO 30 arc second bathymetry were also applied to compare the travel times of the Tohoku-originated tsunami, particularly at Rodrigues in the Indian Ocean and King Edward Point in the Atlantic Ocean with observation-based estimates. At both locations the finite-difference model produced the shortest arrival times, while the ray method produced the longest arrival times. Values of the travel time difference however appear to be within tolerable ranges, considering the propagation distance of the tsunami waves. The observed tsunami at Rodrigues, Mauritius in the west of the Madagascar was found to take a clockwise travel path around Australia and New Zealand, while the observed tsunami at King Edward Point in the southern Atlantic Ocean was found to traverse the Pacific Ocean and then passed into the Atlantic Ocean through the Drake Strait. The formation of icebergs captured by satellite images in Sulzberger in the Antarctica also supports the long-range propagation of the Tohoku-originated tsunami.

Tidal and tide-induced residual currents around Hampyung Bay and Hajae Peninsula by numerical simulation (수치모형을 통한 함평만과 해제반도 주변해역의 조류 및 조석잔차류 분포)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.56 no.2
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    • pp.114-125
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    • 2020
  • In order to understand the currents around Hampyung Bay and Haeje Peninsula, 2D numerical simulations for tidal currents and tide-induced residual currents were carried out. Dominant semidiurnal tidal currents have reversing form and flow NNE-SSW from northern Haeje Peninsula to Songi Island, E-S at northern Haeje Peninsula and NNW-SSE in Hampyung Bay. In flood, a part of currents from Imja Island~Nakwhol Island flow along the main stream flowing northeast at offshore region and the rest flow into Hampyung Bay flowing east along the northern coast of Haeje Peninsula. In ebb, currents from Hampyung Bay flow west along the northern coast of Haeje Peninsula and run together with the main stream flowing southeast at offshore region. The currents create an anticyclonic circulation in flood and a cyclonic circulation in ebb around Haeje Peninsula including Hampyung Bay. Tidal currents are accumulated on Doripo which located at the entrance of Hampyung Bay and show high current velocities. Tidal currents and tide induced residual currents are weak at the inside of Hampyung Bay which has narrow entrance, shallow water depth and wide intertidal zone. An anticyclonic eddy is formed around Gaksi Island as a result of tide induced residual currents. In northern coast of Haeje Peninsula, slow constant currents flow east. It is expected that a gradual change of sediment and an increase of flushing time for suspended materials are carried by tidal currents occurring in Hampyung Bay.

An Analytical Model with Three Sub-Regions for $M_2$ Tide in the Yellow Sea and the East China Sea

  • Jung, Kyung-Tae;Park, Chang-Wook;Oh, Im-Sang;So, Jae-Kwi
    • Ocean Science Journal
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    • v.40 no.4
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    • pp.191-200
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    • 2005
  • In this study an analytical tide model of uniform width with three sub-regions is presented. The three-subregions model takes into account step-like variations in depths in the direction of the channel as a way to examine the $M_2$ tide of the East China Sea (ECS) as well as the Yellow Sea (YS). A modified Proudman radiation condition has been applied at the northern open head, while the sea surface elevation is specified at the southern open boundary. It is seen that, due to the presence of an abrupt change in depth, co-amplitude lines of the $M_2$ tide are splitted to the east and west near the end of the ECS shelf region. Variations in depths, bottom friction and the open head boundary conditions all contribute to the determination of formation of amphidromes as well as overall patterns of $M_2$ tidal distribution. It is seen that increasing water depth and bottom friction in the ECS shelf results in the westward shift of the southern amphidrome. There is however no hint at all of the well-known degenerated tidal pattern being formed. It is inferred that a lateral variation of water depth has to be somehow incorporated to represent the tidal patterns in ECS in a realistic manner. Regarding the radiation factor introduced by Fang et al. (1991), use of a value larger than one, possibly with a phase shift, appears to be a proper way of incorporating the reflected waves from the northern Yellow Sea (NYS).