• Title/Summary/Keyword: Korea Coastal Current

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Chemical Imprints of the Upwelled Waters off the Coast of the Southern East Sea of Korea

  • Lee, Tong-Sup;Kim, Il-Nam
    • Journal of the korean society of oceanography
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    • v.38 no.3
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    • pp.101-110
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    • 2003
  • We made intensive observations on the coastal upwelling off the coast of the southern East Sea from June to August in 2001. The upwelling exhibited a weekly waxing and waning. The coastal upwelling of the year 2001 was characterized by abrupt outbreaks and the small local scale. Upwelling occurred more frequently off the coast of Ulsan and Gampo as reported by the earlier observers. The spread of freshly upwelled colder water was varied by each upwelling event. Generally cold waters were carried away northeastward off Pohang province. The upwelled cold waters were saltier than the resident surface waters. The pH and salinity-normalized alkalinity support the idea that the upwelled waters originate from the interior of the East Sea. The extraordinarily high concentration of dissolved oxygen suggests that the upwelled waters are closely connected to the southward flowing North Korea Cold Current. Although a lower primary productivity was reported for the upwelling region, underway surface fluorescence measurement revealed that the recently upwelled waters supported up to an order of magnitude higher algal biomass than the ambient waters. Because thermohaline circulation of the East Sea is so vigorous, with an estimated time scale of less than one hundred years, that the coastal upwelling should be considered not as an anomaly but as a regular component of a circulatory system. A quantitative understanding of upwelling seems to be a key to elucidate material cycling and the associated biological production in the East Sea.

An Economic Approach to Compensation Practices for Fisheries Damages of Korea (우리나라 어업손실 보상제도에 대한 개선방안연구;-경제적 접근방법을 중심으로-)

  • 표희동
    • The Journal of Fisheries Business Administration
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    • v.25 no.1
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    • pp.1-17
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    • 1994
  • Coastal economic activities usually generate externalities to other economic activities. The conflicts between coastal economic activities, especially land fillings and reclamations, and fisheries in coastal waters pose a typical one, which sometimes causes some social conflicts. In this regard, as the contents and requirements for rules and regulations on fisheries compensation may have important implications for solving such problems, important is to review rationales fur the formulas in calculating fisheries compensation. The purpose of this paper is to review the formulas for fisheries compensation from the economic view points, to highlight some problems and to suggest more appropriate formulas. It is found that the current formulas of fisheries compensation are not properly based on economic concepts and valuation techniques. Main problems are related, as followings, to the coefficient(0.8) employed in the formula, to fishermen's own wages and to current values of invested assets such as fishing boats and nets, etc.. First, it is not clear what the coefficient(0, 8) means. In Japan's case, the coefficient was assumed to reflect the opportunity cost of fishermen's own wages, but it was disappeared from the formula after the self-wage came to be included in totaling fishing cost. As our new formula will include the self-wage in fishing cost, the coefficient(0.8) should be excluded. Second, according to our formula, the current value of invested assets is added to total operating compensation, which will overestimate total compensation. Therefore, it is suggested that total present value of the assets to be invested during the business life should be deducted from total operating compensation. Third, as the self-wage will be included in total cost, opportunity cost for finding new jobs should be newly added to the formula. Finally, this paper also conducted a comparative case study considering above-mentioned factors. The case study showed that the current formulas overestimated total fisheries compensation.

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Selecting the Geographical Optimal Safety Site for Offshore Wind Farms to Reduce the Risk of Coastal Disasters in the Southwest Coast of South Korea (국내 서남해권 연안재해 리스크 저감을 위한 지리적 해상풍력단지 최적 입지 안전구역 선정 연구)

  • Kim, Jun-Gho;Ryu, Geon-Hwa;Kim, Young-Gon;Kim, Sang-Man;Moon, Chae-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.5
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    • pp.1003-1012
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    • 2022
  • The horizontal force transfer to the turbine and substructure of a wind power generation system is a very important factor in maintaining the safety of the system, but it is inevitably vulnerable to large-scale coastal disasters such as earthquakes and typhoons. Wind power generation systems built on the coast or far offshore are very disadvantageous in terms of economic feasibility due to an increase in initial investment cost because a more robust design is required when installed in areas vulnerable to coastal disasters. In this study, the GIS method was used to select the optimal site for a wind farm from the viewpoint of reducing the risk of coastal disasters. The current status of earthquakes in the West and South Seas of Korea, and the path and intensity of typhoons affecting or passing through the West and South Seas were also analyzed. Accordingly, the optimal offshore wind farm site with the lowest risk of coastal disasters has been selected and will be used as basic research data for offshore wind power projects in the region in the future.

Improvement Strategies for Coastal Zone Safety Facilities through Analysis of Domestic and Foreign Field Survey (국내외 실태조사 분석을 통한 연안역 안전시설의 개선방향)

  • Bae, Hyun-Ung;Yi, Gyu-Sei;Lee, Chin-Ok;Lim, Nam-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.1
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    • pp.478-484
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    • 2013
  • Recently, the risk of safety accidents in the coastal zone has been increased due to revitalization of marine leisure and tourism. Because of a lack of regulations about technical and maintenance aspect for safety facilities, the effective measures to prevent safety accidents in the coastal zone have not taken with increasing rate of the accidents. The nature of land/sea and behavioral characteristics of a fisherman/port laborer/tourist/people at leisure should be taken into account properly when safety facilities to prevent safety accidents in the coastal zone are installed, since the characteristics of land/sea and many activities such as fishery, harbor works, tour, leisure are mixed in the geographic and environmental condition of the coastal zone. This study analyzes the current problems on the safety facility in the domestic coastal zone through the domestic and foreign(Hongkong, Macau) field survey. Also the direction of the improvement about the safety facility are proposed.

Comparison of RIAMOM and MOM in Modeling the East Sea/Japan Sea Circulation

  • Lee, Ho-Jin;Yoon, Jong-Hwan;Kawamura, Hideyuki;Kang, Hyoun-Woo
    • Ocean and Polar Research
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    • v.25 no.3
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    • pp.287-302
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    • 2003
  • The seasonal variations in the circulation of the water mass in the East Sea/Japan Sea have been simulated using a free surface primitive ocean model, RIAMOM (RIAM Ocean Model), comparing the results from GFDL-MOM1 (Geophysical Fluid Dynamics Laboratory Modular Ocean Model, version 1.1, hereafter MOM) with the GDEM (Generalized Digital Environmental Model) data. Both models appear to successfully reproduce the distinct features of circulation in the East Sea/Japan Sea, such as the NB (Nearshore Branch) flowing along the Japanese coast, the EKWC (East Korean Warm Current) flowing northward along the Korean coast, and the NKCC/LCC (North Korean Cold Current/Liman Cold Current) flowing southwestward along Korean/Russian coast. RIAMOM has shown better performance, compared to MOM, in terms of the realistic simulation of the flow field in the East Sea/Japan Sea; RIAMOM has produced more rectified flows on the coastal region, for example, the narrower and stronger NKCC/LCC than MOM has. There is however obvious differences between the model results and the GDEM data in terms of the calculation of the water mass; both models have shown a tendency to overpredict temperature and underpredict salinity below 50m; more diffusive forms of thermocline and halocline have been simulated than noted in GDEM data.

Satellite data analysis of the China Coastal Waters in the Seas surrounding Jeju Island, Korea

  • Yoon, Hong-Joo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.344-347
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    • 2006
  • China Coastal Water (CCW) usually appears in the seas surrounding Jeju Island annually (June?October) and is very pronounced in August. The power spectrum density (PSD), sea level anomalies (SLAs), and sea surface temperatures (SSTs) were found to peak annually and semiannually. The peaks at intervals of 80-, 60-, and 43-days are considered to be influenced by CCW and the Kuroshio Current. Generally, low-salinity water appears to the west of Jeju Island from June through October and gradually propagates to the east, where CCW meets the Tsushima Current. Empirical orthogonal function (EOF) analysis of SLAs and SSTs indicated that the variance in SLAs and SSTs was 55.70 and 98.09% in the first mode, respectively. The PSD for the first mode of EOF analysis of SLAs was stronger in the western than in the eastern waters because of the influence of CCW. The PSD for the EOF analysis of SSTs was similar in all areas (the Yangtze Estuary and the waters to the west and east of Jeju Island), with a period of approximately 260 days.

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Current -Drpth Refraction and Diffraction Model for Irregular Waves (수심 및 흐름의 영향에 의한 굴ㆍ회절을 고려한 불규칙파 모형)

  • Jeong, Shin-Taek;Chae, Jang-Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.3
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    • pp.260-265
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    • 1994
  • A new set of elliptic wave equations describing the deformations of irregular waves on a large-scale current field in water of irregular depth is given, and using finite difference scheme an efficient numerical method is also presented. The elliptic equations are solved in a similar way to Initial value problem. This method is extensively used for the calculation of wave spectral transformation. and computation results agree very well with experimental data (Hiraishi, 1991). Finally numerical examples are presented concerning the interactions between waves and currents over a mildly sloping beach and also over a mound.

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Depth Contours Appeared on SAR Images by Interactions Between Tidal Currents and Bottom Topography

  • Kim, Tae-Rim
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.415-419
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    • 2006
  • X-SAR images taken on the coastal waters of Hwanghe province in Korea during SIR-C/X-SAR campaign in April and October 1994 are analysed. The SAR images show the peculiar signatures like nail marks, curved long string, and vortex street patterns and they all seem to be produced by strong interactions between the topography in the coastal waters and tidal currents. The nail mark signatures are located at the same position of small scaled sand banks and the curved line patterns are almost identical to the outer boundary of large sand banks. Based on the tidal records, all the three images are taken at the almost same phase of tidal cycles, which are close to the low tide. It seems that bottom shapes are more strongly appeared on the SAR images when the tidal currents are slow. The front between two different current velocities caused by the flows along the steep boundaries of sandbanks is also the main factors imprinting the bottom features to the sea surface SAR images.

Current Speed Measurements by Using Ocean Acoustic Tomography of Reciprocal Sound Transmission in the Southern Water of Koje Island (거제도 남쪽해역에서 쌍방향 음파전파 해양음향 토모그래피를 이용한 유속측정)

  • Byun, Sang-Kyung;Kim, Bong-Chae;Cnoi, Bok-Kyoung;Kaneko, Arata;Gohda, Noriaki
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.3
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    • pp.161-169
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    • 1999
  • In order to investigate the validity of acoustic tomography for current measurement, an experiment of reciprocal sound transmission was conducted in April, 1997 in the southern water of Koje island. This experiment was attempted as a preliminary field study on coastal ocean acoustic tomography for construction of real-time current observation system. Examining the physical oceanography environments, the current data obtained by travel time difference of reciprocal sound wave was compared with the data of Acoustic Doppler Current Profiler (ADCP). The result shows the correlation coefficient of 0.943, very good relation between the two data, and therefore the ocean acoustic tomography could be a useful method for current measurement in the coastal area.

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Hydrography and Sub-tidal Current in the Cheju Strait in Spring, 1983 (1983년 춘계 제주해협의 해황과 해류)

  • Chang, Kyung-Il;Kim, Kuh;Lee, Suk-Woo;Shim, Tae-Bo
    • 한국해양학회지
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    • v.30 no.3
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    • pp.203-215
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    • 1995
  • Two hydrographic surveys along with direct current measurements using drogues and moored current meters were conducted in Cheju Strait during April and May, 1983. The data clearly demonstrate that a branch of the Kuroshio characterized by high temperature and high salinity enters the Cheju Strait after turning around the western coast of Cheju-Do. The width of the current turning west of Cheju-Do is about 60 km and reduces to 20∼30 km in the strait, resulting in a high speed(>10 cm/s) at the western entrance and in the middle of the strait, compared with a low speed (>5 cm/s) west of Cheju-Do. The Tsushima Current water also originating from the Kuroshio shows its influence in the eastern part of the Cheju Strait. Thermohaline fronts formed between the warm current waters and the coastal waters suggest the southward extension of the Yellow Sea Coastal Water west of the Cheju Strait. A warming of the warm current waters occurs in May, while a cooling takes place in other areas. The major freshening and cooling of water take place in the middle of the Cheju Strait in May due to the intrusion of cold and low salinity water from the west of the Cheju Strait.

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