• 제목/요약/키워드: ocean tides

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A Comparative Study for Red Tide Detection Methods Using GOCI and MODIS

  • Oh, Seung-Yeol;Jang, Seon-Woong;Park, Won-Gyu;Lee, Jun-Ho;Yoon, Hong-Joo
    • 대한원격탐사학회지
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    • 제29권3호
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    • pp.331-335
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    • 2013
  • This study detected red tide areas using the existing Moderate-Resolution Imaging Spectroradiometer(MODIS) and Geostationary Ocean Color Imager(GOCI), and then compared the results between results of two sensors. The coasts of Jeollanam-do in the South Sea of Korea were set as the study area based on the red tide data which occurred on Aug. 26th, 2012. This study compared the results of sensors to detect red tides by using a satellite. In the results of analyzing MODIS by limiting it as chlorophyll concentration and the sea surface temperature which is considered to have red tides by the existing researches, it was possible to delete considerable amount of errors compared to the case of detecting red tides by using only chlorophyll while still there were differences from the range of red tides actually observed. In the results of GOCI by using empirical algorithm for detecting red tides, currently used by Korea Institute of Ocean Science & Technology(KIOST), it was possible to obtain more detailed results than MODIS. However, there was an area misjudged as red tides due to the influence of clouds. Also both MODIS and GOCI extracted red tides were not actually occurring, which might be because they were not able to perfectly distinguish red tides from turbid water in coastal areas with high turbidity.

해양 신재생에너지의 고찰 (An Overview of Marine Renewable Energy)

  • 김용천
    • 한국해안·해양공학회논문집
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    • 제25권6호
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    • pp.433-438
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    • 2013
  • 에너지 자원의 부족이 점진적으로 증가할 것이라는 전망과 함께 재생가능한 대체 에너지에 대한 관심이 증가하고 있다. 잠재적인 재생가능에너지의 보고인 대양으로부터 에너지를 추출하는 방법을 고안하는 노력이 증가하고 있다. 본 논문은 해양 파랑, 조석, 온도차, 해류 등의 해양 신재생에너지 자원의 추출 및 변환의 연구동향을 요약 검토하였다. 각각의 에너지 추출과 변환 기술을 사례별로 논의하였다.

2003년 태풍 매미로 인한 부산 연안지역의 재해특성 분석 (Disaster Characteristics Analysis at Busan Coastal Areas by Typhoon Maemi in 2003)

  • 서규우
    • 한국해양공학회지
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    • 제18권2호
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    • pp.25-32
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    • 2004
  • We surveyed the coastal structure damage created by typhoon ‘Maemi’, which heavily struck the Korean peninsula on September 12, 2003. The survey revealed that high tides and strong winds induced by the typhoon were the main causes of the coastal damage, especially in the Busan areas. Though some experimental real-time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete system should be implemented to save human lives and property from huge typhoon disasters.

Development of a Nowcast System for the Taiwan Strait (TSNOW): Numerical Simulation of Barotropic Tides

  • Jan, Sen;Wang, Yu-Huai;Chao, Shenn-Yu;Wang, Dong-Ping
    • Ocean and Polar Research
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    • 제23권2호
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    • pp.195-203
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    • 2001
  • A fine-grid (3 km ${\times}$ 3 km), three-dimensional nowcast system of sea levels, currents, temperature, and salinity is being developed for the Taiwan Strait. The project takes a balanced approach relying equally on models and observations, will have the capacity of real-time data assimilation, and is aimed at both practical and scientific applications. To determine boundary conditions and verify model results, eight coastal tide-gauge stations were first established along both sides of the strait. Strait-wide hydrographic surveys were conducted by research vessels. Currents are being measured using bottom-mounted ADCP moorings in a meridional deep channel off southwest Taiwan and along a traverse section in the central part of the strait. In addition to a fine-resolution three-dimensional model of the Taiwan Strait, an adjoint model and a larger-domain two-dimensional model were used to better determine boundary conditions in the northern and southern boundaries of the strait. In the first stage of model development, barotropic tides were successfully simulated in a hindcast mode. The protocol product has been released to general public, including government agencies, universities and general users.

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Detecting red tides in turbid waters

  • Yoo, Sin-Jae;Jeong, Jong-Chul
    • 대한원격탐사학회지
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    • 제15권4호
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    • pp.321-327
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    • 1999
  • As an example of many possible applications of OSMI data, we present a method to detect red tides. In Korean waters, red tides usually occur in the South Sea where the turbidity is usually high due to strong tidal mixing in the shallow sea. The conventional case 1 chlorophyll algorithm cannot be applied since it cannot distinguish chlorophyll from SS (suspended sediments). In October 1998, a red tide outbreak occurred off the coast of KunSan. We analyzed the SeaWiFS data of the outbreak. The standard SeaWiFS chlorophyll algorithm OC-2 was poor in identifying the red tides. However, comparison of spectra of normalized water-leaving radiance indicates that red tide pixels can be distinguished from sediment-laden pixels. Channel 443 and 555 were effective in showing the spectral characteristics. We suggest K490 algorithm as an example in summarizing the information of the spectra and thereby in distinguishing the red tide pixels. Further development is desirable.

Nutrients And Chlorophyll $\alpha$ Variations At A Fixed Station During The Red Tides In The Jinhae Bay

  • Yang, Dong-Beom;Hong, Gi-Hoon
    • 한국해양학회지
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    • 제17권1호
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    • pp.19-26
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    • 1982
  • 12 or 25 hours continuous observations were made for the variations of nutrients and chlorophyll ${\alpha}$ with tidal cycle at a fixed station located at a mid-channel of the Masan Bay. High nitrate concentrations were observed at the time of low tides whereas high phosphate concentrations at the time of high tides. It is suggested that anoxic bottom waters could also be the possible source of high phosphates in the outer bay. Chlorophyll ${\alpha}$ concentrations were related to the nitrates in April and to the phosphates in June and August. The possible role of growth stimulators in causing the extensive blooms of red tide organisms is suggested.

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인천항 조석의 신속 예보 (Rapid Tidal Predictions for the Inchon Bay)

  • 최병호
    • 한국해안해양공학회지
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    • 제7권4호
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    • pp.355-367
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    • 1995
  • 정점에서의 조석(조위, 조류)은 전통적으로 조화분석 및 예보에 의해 추정되며 다른 방법은 조석수치모형에 의한 예보이다. 본 연구에서는 수치모형의 직접적인 출력으로서 조석을 추정하는 방법과 장기간(1개월)의 모형출력을 조화분석한 조위와 조류의 조화상수의 Data Table을 근거로 한 인천항 전역의 임의위치에서의 실시간적으로 조석을 신속하게 추정하는 방법을 제시하였다.

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한국 남서해역의 조사 산정 (Tidal Computations for the Southwestern Sea of Korea)

  • 최병호;정홍화;조양기
    • 한국해안해양공학회지
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    • 제7권2호
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    • pp.163-169
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    • 1995
  • 2차원 조석모형을 이용하여 한국 남서해역의 주요 8개 분조(M$_2$, S$_2$, $K_1$, $O_1$, $N_2$, $K_2$, P$_1$, Q$_1$)에 대하여 조석도와 조류타원도를 제시하고 관측지와 비교하였다. 모델결과 본 해역에서는 반일주조가 우세한 조석의 형태를 보인다. 제주해협의 조류에 의한 최대 수송량은 약 4.2$\times$$10^{6}$ ㎥/sec로 추산되며 이는 해류에 의한 수송량의 약 8배이다.

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천해조가 발달된 하구에서의 조석파 전파특성 (Tidal Propagation Characteristics in the Estuary which shows Significant Shallow Tides)

  • 강주환;문승록
    • 한국해안해양공학회지
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    • 제13권1호
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    • pp.56-60
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    • 2001
  • 하구입구에서 형성된 조석비대칭 현상은 천해조의 성장에 따라 상류방향으로 갈수록 더욱 심화되는 경향이 있다. 따라서 이러한 해역에서의 유사이동 또는 오염확산 등과 관련된 연구를 수행할 경우 천해조에 대한 면밀한 관찰과 세힘한 적용이 요구된다. 본 연구의 목적은 다양한 수치실험을 통해 천해조의 발생 및 전파에 관한 제반 특성을 밝혀내는데 있으며, 특히 조간대가 조석파의 전파와 천해조 발생에 미치는 영향성에 대하여 중점적으로 연구하였다. 이와 같은 연구를 통해 하구의 지형학적 특성에 따른 조석파의 거동이 규명되면 향후 대규모 토목사업 시행시 천해조를 포함한 조석환경의 변화와 그에 따른 유사 및 오염물질 이동에 관한 정성적인 분석과 더불어 해당해역에서의 조석에 관한 수치모형 설계에도 지침이 될 수 있을 것이다.

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