• 제목/요약/키워드: coastal area sea water

검색결과 615건 처리시간 0.025초

The Fluctuation Characteristics of the Water Mass and the Current Structure of the Southeastern Region of The East Sea

  • Lee Chung Il;Cho Kyu Dae
    • Fisheries and Aquatic Sciences
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    • 제3권2호
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    • pp.97-110
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    • 2000
  • To investigate characteristics of water masses and current structures around Noto Peninsula located in south-east coastal region of the East Sea, observation results of CREAMS (Circulations Research of the East Asian Marginal Seas) cruise and data report of oceanographic observation (Japan Meteorological Agency) in June, 1995 and 1996 were used. Water mass showing characteristics of Tsushima Warm Current (TWC) exists over the continental shelf. The depth is shallower than 200m and its width and thickness are 190km and 200m, respectively. Minimum level of dissolved oxygen occurred at the layers of maximum salinity. In the current structure, a noteworthy phenomenon is that the positions of the high-salinity water (more than 34.6 psu) match well with the distributions of the southwestward flow. In June of 1995 and June of 1996, a southwestward flow were separated into two parts along line C and line G. Current directions derived from the temperature and salinity match well with the distributions of the geostrophic currents in the vertical sections. The isothermal lines and the isohaline, which exist horizontally along the coastal area of the Japan, change abruptly at the frontal area of the Noto Peninsula, then turn toward the center of the East Sea. The dynamic depth anomalies centering around the region far northwest of the Noto Peninsula were relatively high, compared to those of other regions. The isopycnic surface (sigma-t, 25.8) existed near the surface in the central part of the East Sea, but, at the depth of 100m, the isopycnic surface was found in the coastal waters.

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제주도 연안해수의 영양염류에 관한 연구 (Distribution of Nutrients in the Coastal Sea of Jeju Island)

  • 박길순
    • 한국수산과학회지
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    • 제15권4호
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    • pp.255-262
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    • 1982
  • 1. 일반적으로 제주도 연안역에서의 영양염류 농도는 성분에 따라 차이가 있으나 표층보다 50 m이심에서의 농도가 $0.5\sim3$배 정도 높다. 2. 제주도 남동쪽 해역의 수온, 염분과 규산염, 질산염, 인산염, 용존산소의 농도 분포가 단조롭고 비교적 각 성분의 량도 적다. 3. 제주도 북쪽 해역은 한국남안연 안수의 영향을 받아 각 성분의 농도 분포가 복잡하고 그 변동 범위도 크다. 또 영양염류도 이 해역이 남동쪽 해역보다 풍부하다. 4. 제주도 남서쪽 해역은 황해저층냉수의 영향을 받아 영양염이 풍부하나 황해난류와 만나는 호경역이므로 그 분포상은 매우 복잡하다.

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제주도 주변해역의 해양환경요인과 멸치 난자치어 분포 (Environmental Factors and the Distribution of Eggs and Larvae of the Anchovy (Engraulis japonica) in the Coastal Waters of Jeju Island)

  • 고준철;유준택;노홍길
    • 한국수산과학회지
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    • 제40권6호
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    • pp.394-410
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    • 2007
  • Anchovy spawn from the end of May to mid-October, when the water temperature is $14.8-27.2\;^{\circ}C$ and the salinity is 26.0-33.6 psu. The main spawning season is between July to August, when the water temperature is $21.7-27.2\;^{\circ}C$ and the salinity is between 26.0-32.2 psu. The main spawning grounds of anchovy are coastal areas shallower than 50 m around the islands located in the Jeju Strait. Anchovy larvae are distributed near the fronts between Chuja-do, Jangsu-do, Yeoseo-do, and the open sea rather than in the spawning grounds. Anchovy eggs and larvae density increased in accordance with the high level of $Chlorophyll-{\alpha}$ during the summer season (July-August). In terms of the suspended sediment (SS) levels along the northern coast of the Jeju Strait, high densities of anchovy eggs (12.0-18.0 mg/L) were observed, mainly in the area affected by the coastal waters of the southern sea with high SS levels, while larvae (10.0-19.0 mg/L) tended to be distributed over a wide area with high SS levels, including the open sea. In terms of the dissolved oxygen (DO) content, eggs (5.4-6.8 mg/L) were observed in coastal areas with a high DO content, while larvae (4.2-6.4 mg/L) were distributed widely in areas with a relatively low DO content, from the southern coast to the open sea.

한국 남해안의 멸치(Engraulis japornicus) 난자치어 수송에 관한 연구 (A Study on the Transport of Anchovy Engraulis japornicus Egg-larvae in the South Sea of Korea)

  • 김동선;배상완
    • 한국환경과학회지
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    • 제20권11호
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    • pp.1403-1415
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    • 2011
  • To understand the transport of anchovy egg-larvae, an integrated model consisting of a hydrodynamic model and a three-dimensional Lagrangian diffusion model was used for the anchovy Engraulis japornicus egg-larvae trace. Fist, in order to determine the circulation characteristics of the South Sea of Korea, residual flow according to tide, density and wind effect was investigated. In offshore regions, tide-induced residual current tends to flow eastward during the spring tide and westward during the neap tide. Residual flow is irregular due to the bottom topography in the coastal area. No special tendency was apparent in the open sea. Especially, the flow in the offshore regions showed results similar to that of the Tsushima Warm Current. The transport of anchovy egg-larvae is decided the physical properties of sea water. It is estimated that anchovy eggs spawned near the Jeju Island travels offshore, rather than to coastal areas, and grow in the front area between the coastal sea and offshore regions.

담수유입에 의한 식물플랑크톤의 대량번식 후의 연안 수질변동 특성 (Characteristics of Coastal Water Quality after Diatom Blooms Due to Freshwater Inflow)

  • 이영식;박영태;김귀영;최용규;이필용
    • 해양환경안전학회지
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    • 제12권2호
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    • pp.75-79
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    • 2006
  • 연안해역의 수질특성 및 일차생산 증가 메커니즘을 이해하는 데에 기초 자료로 활용하기 위하여, 많은 양의 담수 유입 후 규조류가 대량 번식한 상태와 담수가 유입되지 않고 적조가 발생하지 않은 상태의 해수의 수질특성을 조사차였으며 그 결과를 요약하면 아래와 같다. 1) 호우로 많은 양의 담수가 유입된 해역에서 규조류인 Skeletonema costatum와 Thalassiosira spp.가 각각 $1,200{\sim}5,000cells/mL,\;750{\sim}1,200cells/mL$의 농도로 관찰되었다. 2) 규조류가 대량으로 증식하지 않은 곳보다 규조류가 대량으로 증식한 곳에서 수온, PH, 용존산소농도가 높게 조사되어, 두 곳 사이의 거리가 20m 정도에 불과함에도 불구하고 두 곳의 수질특성 차이는 뚜렷하게 나타났다. 3) 규조류가 대량으로 증식하지 않은 곳보다 규조류가 대량으로 증식한 곳에서 질소 인, 규소의 농도가 낮게 조사되어, 호우로 질소, 인, 규소보다는 규조류가 증식하기 위해 필요한 미량원소가 육지로부터 풍부하게 유입된 것으로 보인다. DIN/DIP, $DIN/SiO_2-Si$ 비는 모두 규조류가 대량 증식한 정점과 그렇지 않은 정점간의 뚜렷한 차이는 없었다.

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Paleoceanographic Records from the Northern Shelf of the East China Sea since the Last Glacial Maximum

  • Li, Bao-Hua;Park, Byong-Kwon;Kim, Dong-Seon
    • Journal of the korean society of oceanography
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    • 제34권3호
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    • pp.151-166
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    • 1999
  • Both benthic and planktonic foraminifera from Core 97-02 obtained in the northern East China Sea are quantitatively analyzed for reconstructing the paleocenography of late Quaternary. Since the earliest time of the core sediment (last not older than 18000 yr B.P.), the paleo-water depth has changed from less than 20 m to near 100 m at present, which is reflected by the benthic foraminiferal assemblages: before 14000 yr B.P., the water depth was shallower than 20 m; from 14000 to 7500 yr B.P., water depth was 20-50 m; and after 7500 yr B.P., water depth was 50-100 m. The foraminiferal fauna also disclose the water mass history: during the last glacial maximum, the water that dominated the study area might be the coastal water; at the end of the last glacial maximum(14000-9500 yr B.P.), the Yellow Sea Cold Water mostly affected this area; then it gave way to the Yellow Sea Warm Current after 9500 yr B.P.; and finally, the warm water has dominated this area since 9500 yr B.P. because of the westward shift and enhancement of the Kuroshio Current.

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한반도 근해의 해류와 해수특성 1. 여름철 한국 남해 표층수중 클로로필과 영양염의 농도분포에 영향을 주는 물리적 과정 (A Study on Sea Water and Ocean Current in the Sea Adjacent to Korea Peninsula 1. Physical Processes Influencing the Surface Distributions of Chlorophyll and Nutrient in the Southern Sea of Korea in Summer)

  • 양한섭;김성수
    • 한국수산과학회지
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    • 제23권6호
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    • pp.417-424
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    • 1990
  • 여름철 한국남해 표층수중 영양염류 및 클로로필의 수평분포와 그 분포에 영향을 주는 물리적과정에 대하여 연구했다. 그 결과, 제주도를 중심으로 북서쪽해역이 남동쪽해역보다 영양염류 및 클로로필의 농도가 높았다. 영양염류 농도로 볼 때 북서쪽 해역은 다시 $2\~3$개의 소구역으로 나눌 수 있다. 그중 $34^{\circ}N$ 이북해역에서는 강한 수온전선이 형성되어 있고, 영양염류 및 클로로필의 농도가 상당히 높았으며, 이는 강한 수직혼합에 의한 것으로 판단된다. 또한 제주도 서쪽해역은 중국대륙치안수의 확장에 의해 표층수중 영양염류가 비교적 풍부하나 클로로필의 농도는 그다지 높지 않았다. 그러나 제주도 주변 연안해역에서는 클로필의 농도가 상당히 높은데, 이는 연안용승작용에 의해 기초생산력이 높아지기 때문이라 생각된다. 여름철 본 조사해역의 표층수중 용존영양염류 및 클로로필의 수평농도분포는 생물화학적 과정보다는 주로 지리적 차이에 따른 수직혼합 혹은 성질의 다른 수괴의 수평확산에 의해 좌우된다.

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The oceanic condition of the Tsushima Warm Current region the southern part of the East Sea (Sea of Japan) In June, 1996

  • 이충일;조규대
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2003년도 추계학술발표회
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    • pp.167-174
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    • 2003
  • Oceanic conditions of the Tsushirm Wann Current (1WC) region in the southern area if the East Sea (the Japan Sea) are examined using data obtained from a CREAMS (Circulation Research if the East Asian Marginal Seas) cruise in June 1996. In 1990s, a lower temperature appears in $19\%$ and in this period, two branch of the TWC exist and the first branch of the TWC flows inshore if the Japanese coastal region compared to tfr1t in the other years, especially in the sfr1llower water layer at less th:1n about 2mm. The TWC cored with the higher salinity (>34.6 psu) is clearly observed over the continental shelf zone in the Japanese coastal region and offshore and identified by geostrophic calculation Intrusion if the TWC into the East Sea through the Korea Strait (the Tsushima Strait) makes the density structure in the water column change and the water mass in the TWC region is unstable based on Brunt- Vaisala frequency.

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생태계 모델링을 이용한 부산연안해역 수질개선 예측 (Prediction of Water Quality Improvement by using Ecological Modelling in Busan Coastal Area)

  • 정우성;김진호;김동명
    • 해양환경안전학회지
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    • 제23권5호
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    • pp.524-531
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    • 2017
  • 본 연구는 생태계 모델을 이용하여 부산연안으로 유입되는 부하량 삭감에 따른 해역의 수질개선 정도를 예측하였다. 모델링 결과에 의하면 COD, T-N, T-P 모두 수영만 연안과 낙동강 하구에서 뚜렷한 개선을 나타냈으며, 수영만을 제외한 만 중부에서 만 동쪽까지는 수질개선이 거의 나타나지 않았다. 이는, 부산연안이 남해에 위치한 다른 해역에 비해 개방형경계를 가지고 있어서, 물질교환이 빠르기 때문으로 판단된다. 수질개선을 위한 본 해역의 삭감 COD 부하량은 타 해역에 비해 적었고, 총 유입부하량에 대한 삭감비율 또한 작게 나타났다. 본 연구에 적용한 부하삭감량을 적용하면 수영만, 낙동강 하구부근에서 뚜렷한 수질개선효과를 얻을 수 있을 것으로 판단된다.

간이해역이용협의 유형분석 및 효율적 환경평가방안 (An Effective Environmental Assessment for the Simple Statement of the Sea Area Utilization Consultation System)

  • 이대인;엄기혁;김귀영
    • 환경영향평가
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    • 제22권3호
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    • pp.255-264
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    • 2013
  • This paper diagnosed the assessment problems and development types of the simple statement of the Sea Area Utilization Consultation System. and suggested the key assessment items for system improvement. The major types of Public Water occupation and use, and distribution characteristic of regional and coastal were analyzed by evaluate 529 review items during 2010-2012. The artificial structure installation including harbor and fishing port facilities in the South and West coast, and seawater supply and drainage for land-based aquaculture and power plant were dominated. The checklists considering each types of occupation and use in Public Water were suggested. In addition, policy proposals for system improvement were suggested.