• Title/Summary/Keyword: Ocean current

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Current Observations in the Yellow Sea and the East China Sea Continental Shelf (황해 및 동중국해륙붕에서의 해류관측)

  • 최병호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.5 no.4
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    • pp.414-426
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    • 1993
  • A description is given of the recent techniques employed for the measurement of currents in the East China Sea continental shell The variability of the currents in the region is briefly discussed as it affects the measurement Data sources have been collated to develop an inventory of current observations in the shelf seas around Korea.

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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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BOTTOM FRICTION OF WAVE-CURRENT FLOW ON A NATURAL BEACH

  • Yoo, Dong-Hoon
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1991.07a
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    • pp.6-10
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    • 1991
  • The bottom friction model of combined wave-current flow developed by Bijker, Yoo and O'Conner (hereafter it is called BYO model) is fully based on the Prandtl's mixing length theory. Although the Prandtl's theory is dependant on some rationalism, it is widely recognized that the theory is generally acceptable for the description of any turbulent flow.(omitted)

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Trace Element in the Indian Ocean: Current Research Trends and Future Needs (인도양에서 미량원소 연구 동향 및 향후 연구 방향)

  • Kim, Intae
    • Ocean and Polar Research
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    • v.43 no.4
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    • pp.335-352
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    • 2021
  • Trace elements in the ocean have been known as essential micronutrients for the primary production of phytoplankton and the growth of marine organisms. The GEOTRACES program beginning in the mid-2000 provided a new understanding of the distribution, origin and behavior of trace elements in the ocean, together with the establishment of both clean seawater sampling and trace element analysis techniques. The Indian Ocean, one of the major oceans, is relatively the least explored area, despite playing an important role in global climate variability. Although trace element observations have recently been conducted in the Indian Ocean by Japanese-and Indian scientists, relatively not much study has been done compared to the Atlantic, Pacific and Polar Regions. Recently, together with the launch of R/V Isabu, a 5,000-ton grade large- and comprehensive research vessel, the observations of trace elements has been conducted in the Indian Ocean for the first time in Korea since 2018. In this paper, we introduce the key results of currently conducted GEOTRACES expedition in the Indian Ocean to present future trace element research directions in the Indian Ocean, and also reviewed the preliminary results in the Indian Ocean studies from Korea. In the 2020s, new Indian Ocean GEOTRACES projects are planned around European countries, and it is time for Korea to prepare for the next phase of the trace element study in the Indian Ocean in line with these international trends.

Introduction to COMS Geostationary Ocean Color Imager

  • Kang Gumsil;Kim Jongah;Myung Hwan-Chun;Yeon Jeong-Heum;Kang Song-Doug;Youn Heong-Sik
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.108-111
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    • 2005
  • The Communication Ocean, Meteorological Satellite (COMS) as the one of the national space program has been developed by Korea Aerospace Research Institute (KARl). The Geostationary Ocean Color Imager (GOCI) is one of the main payloads ofCOMS which will provide consistent monitoring of ocean-colour around the Korean Peninsula from geostationary platforms. The ocean color observation from geostationary platform is required to remedy the coverage constraints imposed by polar orbiting platforms. In this paper the main characteristics of GOCI are described and compared with the current ocean color sensors. The GOCI will provide the measurement data of 6 visible channels and 2 nearinfrared channels (40Onm - 900nm). The high radiometric sensitivity is essential of ocean color sensor because of the weak water leaving radiance.

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Mean Characteristics of Temperature, Salinity and Chlorophyll-α at the Surface Water in the Northern East China Sea (동중국해 북부 해역 표층의 평균적 해황과 chlorophyll-α의 분포)

  • Choi, Yong-Kyu;Suh, Young-Sang;Seong, Ki-Tack;Yoon, Won-Duk;Kim, Sang-Woo
    • Journal of Environmental Science International
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    • v.17 no.2
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    • pp.141-148
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    • 2008
  • In order to investigate the effect of inflow of Yangze river on the distribution of chlorophyll-${\alpha}$, the results of serial oceanographic observation during 2000-2005 were used. The oceanographic conditions in the northern East China Sea is influenced by the Tsushima Warm Current and low saline water derived from the Yangze river. The distributions of these water masses vary significantly by the season in the northern East China Sea. The sea surface temperature and salinity were stable and concentrations of chlorophyll-${\alpha}$ were low in the eastern part of $126^{\circ}E$. On the contrary, the salinity was significantly influenced by the low saline water derived from Yangze river with the high concentrations of chlorophyll-${\alpha}$. It is suggested that the low saline water inflowed from the Yangze river affects high concentrations of chlorophyll-${\alpha}$ in the northern East China Sea in summer.

Spatial distribution of pigment concentration around the East Korean Warm Current region derived from Satellite data

  • Kim, Sang-Woo;Kim, Young-Seup;Yoon, Hong-Joo;Saitoh, Sei-ich
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.655-655
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    • 2002
  • Spatial distribution of phytoplankton pigment concentration (PPC) and sea surface temperature (SST) around the East Korean Warm Current (EKWC) was described, using both ocean color images and advanced very high resolution radiometer (AVHRR) images. Water mass in this region can be classified into five categories in the horizontal profile of PPC and SST, nLw(normalized water-leaving radiance) images: (1) coastal cold water region associated with concentrations of dissolved organic material or yellow colored substances and suspended sediments, (2) cold water region of thermal frontal occurred by a combination of phytoplankton absorption and suspended materials, (3) warm water overlay region by the phytoplankton absorption than the suspended materials; (4) warm water region occurred by the low phytoplankton absorption, and (5) offshore region occurred by the high phytoplankton absorption. In particular, the highest PPC area appeared in the ocean color and SST images with a band shaped distribution of the thermal front and ocean color front region, which is located the coastal cold waters along western thermal front of the warm streamer of the EKWC.

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Eddy Current Loss Analysis of Slotless Double-sided Cored Type Permanent Magnet Generator by using Analytical Method (해석적 방법을 이용한 슬롯리스 양측식 코어드 타입 영구자석 발전기의 와전류 손실 해석)

  • Jang, Gang-Hyeon;Jung, Kyoung-Hun;Hong, Keyyong;Kim, Kyong-Hwan;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1639-1647
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    • 2016
  • This paper deals with eddy current loss analysis of Slotless Double sided Cored type permanent magnet linear generator by using analytical method, space harmonic method. In order to calculate eddy current, this paper derives analytical solution by the Maxwell equation, magnetic vector potential, Faraday's law and a two-dimensional(2-D) cartesian coordinate system. First, we derived the armature reaction field distribution produced by armature wingding current. Second, by using derived armature reaction field solution, the analytical solution for eddy current density distribution are also obtained. Finally, the analytical solution for eddy current loss induced in permanent magnets(PMs) are derived by using equivalent, electrical resistance calculated from PMs volume and eddy current density distribution solution. The analytical result from space harmonic method are validated extensively by comparing with finite element method(FEM).

VARIATIONS IN THE SOYA WARM CURRENT OBSERVED BY HF OCEAN RADAR, COASTAL TIDE GAUGES AND SATELLITE ALTIMETRY

  • Ebuchi, Naoto;Fukamachi, Yasushi;Ohshima, Kay I.;Shirasawa, Kunio;Wakatsuchi, Masaaki
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.17-20
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    • 2006
  • Three HF ocean radar stations were installed at the Soya/La Perouse Strait in the Sea of Okhotsk in order to monitor the Soya Warm Current. The frequency of the HF radar is 13.9 MHz, and the range and azimuth resolutions are 3 km and $5^{\circ}$, respectively. The radar covers a range of approximately 70 km from the coast. It is shown that the HF radars clearly capture seasonal and short-term variations of the Soya Warm Current. The velocity of the Soya Warm Current reaches its maximum, approximately 1 m $s^{-1}$, in summer, and weakens in winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately 50 km. The surface transport by the Soya Warm Current shows a significant correlation with the sea level difference along the strait, as derived from coastal tide gauge records. The cross-current sea level difference, which is estimated from the sea level anomalies observed by the Jason-1 altimeter and a coastal tide gauge, also exhibits variation in concert with the surface transport and along-current sea level difference.

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