• Title/Summary/Keyword: Kuroshio

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Sea level observations in the Korean seas by remote sensing

  • Yoon, Hong-Joo;Byon, Hye-Kyong
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.879-881
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    • 2003
  • Sea level variations and sea surface circulations in the Korean seas were observed by Topex/Poseidon altimeter data from 1993 through 1997. In sea level variations, the West and South Sea showed relatively high variations with comparison to the East Sea. Then, the northern and southern area in the West Sea showed the range of 20${\sim}$30cm and 18${\sim}$24cm, and the northern west of Jeju island and the southern west of Tsushima island in the South Sea showed the range of 15${\sim}$20cm and 10${\sim}$15cm, respectively. High variations in the West Sea was results to the inflow in sea surface of Yellow Sea Warm Current (YSWC) and bottom topography. Sea level variations in the South Sea was due to two branch currents(Jeju Warm Current and East Korea Warm Current) originated from Kuroshio Current (KC). In sea surface circulations, there existed remarkably three eddies circulations in the East Sea that are mainly connected with North Korea Cold Current (NKCC), East Korea Warm Current (EKWC) and Tushima Warm Current(TWC). Their eddies are caused basically to the influence of currents in sea surface circulations; Cyclone (0.03 cm/sec) in the Wonsan bay off shore with NKCC, and anticyclone (0.06 cm/sec) in the southwestern area of Ulleung island with EKWC, and cyclone (0.01 cm/sec) in the northeastern area of Tushima island with TWC, respectively.

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Study on the Korean Waters using the CAL/VAL of the OSMI Level 2 Data

  • Suh, Young-Sang;Jang, Lee-Hyun;Mitchell, B.G.;Kahru, M.;Prasad, Kota;Shin, H.Y.
    • Korean Journal of Remote Sensing
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    • v.18 no.3
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    • pp.127-139
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    • 2002
  • A comparison was made between the chlorophyll $\alpha$ and suspended solid (SS) retrievals from OSMI and SeaWiFS sensor to chlorophyll $\alpha$ and SS values determined with the standard method during the NFRDI's research cruises. The percentage of organic and inorganic materials from the SS was calculated to study the contribution of turbid water in the northern part of the East China Sea. The open sea waters in the Kuroshio regions of the East China Sea showed relatively higher concentration of volatile SS. However, towards the northwestern part of the East China Sea, the situation became much more optically different with the non-volatile SS from the Yangtze river and the sea bottom sources in the sea in winter and spring seasons. Furthermore, in order to indirectly detect low salinity water with high turbidity, which related to the Yangtze river using remote sensed data from the satellites, a comparison between the results of the band ratio(nLw 490nm/nLw 555nm) of SeaWiFS(OSMI) and the distribution of low salinity around the Jeju Island was presented.

Temporal and Spatial Variations of SST and Ocean Fronts in the Korean Seas by Empirical Orthogonal Function Analysis

  • Yoon, Hong-Joo;Byun, Hye-Kyung;Park , Kwang-Soon
    • Korean Journal of Remote Sensing
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    • v.21 no.3
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    • pp.213-219
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    • 2005
  • In the Korean seas, Sea Surface Temperature (SST) and Thermal ronts (TF) were analyzed temporally and spatially during 8 years from 1993 to 2000 using NOAA/AVHRR MCSST. In the application of EOF analysis for SST, the variance of the 1st mode was 97.6%. Temporal components showed annual variations, and spatial components showed that where it is closer to continents, the SST variations are higher. Temporal components of the 2nd mode presented higher values of 1993, 94 and 95 than those of other years. Although these phenomena were not remarkable, they could be considered ELNI . NO effects to the Korean seas as the time was when ELNI . NO occurred. The Sobel Edge Detection Method (SEDM) delineated four fronts: the Subpolar Front (SPF) separating the northern and southern parts of the East Sea; the Kuroshio Front (KF) in the East China Sea, the South Sea Coastal Front (SSCF) in the South Sea, and the Tidal Front (TDF) in the West Sea. TF generally occurred over steep bathymetry slopes, and spatial components of the 1st mode in SST were bounded within these frontal areas. EOF analysis of SST gradient values revealed the temporal and spatial variations of the TF. The SPF and SSCF were most intense in March and October; the KF was most significant in March and May.

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

  • Cho, Han-Keun;Kang, Heung-Soon;Kim, Jung-Chang;Yoon, Hong-Joo
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.397-402
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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.

Marine Pollution of the East China Sea by Floating Marine Debris(I) - Temporal quantity distribution of each zone - (부유성 해양 폐기물에 의한 동지나해의 해양오염(I) - 해역별 수량 분포를 중심으로 -)

  • Kim, Jong-Hwa;Kim, Yong-Bok
    • Journal of Fisheries and Marine Sciences Education
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    • v.23 no.4
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    • pp.642-647
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    • 2011
  • In order to analyze the influence of floating marine debris (FMD) in the East China Sea (ECS), a sighting survey was conducted from July 1st to July 14th, 2009 navigating about 966 km using a training vessel "Kaya (1,737 ton)" of Pukyong National University. The sampled zones are divided into 5 transect by observation day during the survey days and again specified with 45 segments per unit hour on the survey routes. The results of distribution of FMD are as follows: 1. The quantities of FMD at the central China Sea(CE) and northern part of Taiwan(NT) were found as total mean of 90.8 ea/hr, 56.7 ea/hr, respectively, and also 36.8 ea/hr, western part of Kyushu district(WJ), 10.7 ea/hr, 8.0 ea/hr, western(OK1) and northern part(OK2) of Okinawa, respectively. 2. Temporal variation of FMD is represented by depicting the sinusoidal curve as shape as tide in CE and OK1. 3. The higher sea surface temperature (SST) is as likely as if Kuroshio current exists strongly, the less quantities are decreased. On the other hand, the coastal zone of ECS and near of Yellow Sea are increased by lower SST.

Water Masses and Circulations around Korean Peninsula (한반도 주변의 수괴와 해수순환)

  • 승영호
    • 한국해양학회지
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    • v.27 no.4
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    • pp.324-331
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    • 1992
  • Water masses and circulations around Korean peninsula are briefly described based on recent studies. The results of theses studies are discussed from the physical point of view. Oceanic conditions in this region are largely due to the roles played by the Tsushima Warm Current, an onshore extension of the Kuroshio, and local conditions such as wind, surface heat flux and fresh water input etc. To the south and west of Korea, the northern/western border of the Tsushima Warm Current Water is roughly the line joining Taiwan and Cheju island. In summer, it is affected by large amount of fresh water discharged from the Changjiang and in winter, an intrusion of this water into the Yellow Sea is induced by the prevailing northwesterly monsoon wind. To the east of Korea, the Tsushima Warm Current Water presents roughly south of the line joining the wast coast of Korea near 37-38$^{\circ}$N and Tsugaru-Soya Straits in the northern Japan. But this situation, together with those in deeper layers, may greatly be changed by winter atmospheric conditions (wind and surface heat flux). The seas around Korea are not yet physically well understood and many problems wait physical explanations. Some problems, along with personal views of them, are mentioned.

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Some Comments on the Preparation of the CSK Standard Chemical Solutions (CSK Standard Chemical Solution 과 그에 대한 몇가지 의견)

  • Won, Chong Hun
    • 한국해양학회지
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    • v.4 no.2
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    • pp.83-86
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    • 1969
  • 해양관측의 세계적인 공통성으로 해서 염분검정법이 이미 오래 전부터 통일화 되었지만 근래에 와서는 용존산소량 정량법도 국제적인 Intercalibration을 하는 등규격화에의 기운이 나고 있다. 다시 Kuroshio 합동조사에서는 영양염의 정량에 있어 공통된 표준용액을 사용하므로써 조작상의 편리와 측정치의 신뢰성을 더욱 향상시키자는 의도에서 일본이 국제적인 영양염 표준용액의 조제 및 배포에 관한 안을 내어 1965년 Manila 회의를 거쳐 일본 상모중앙화학연구소의 관원씨가 이를 맡아 1966년부터 시작하여 1967년까지에 요오드산칼리움, 아질산염, 인산염, 규산염의 표준용액을 만들어 1968년 봄부터 시험적으로 일본국내와 동남아 수개국에 나누어 사용해 왔던 것이다. 다시 1968년 9월의 SCOR 의 영양염에 관한 Working Group 회의에서 CSK Std. Solution을 사용하여 세계각국에서 현재 사용하고 있는 영양염 분석방법의 Intercalibration을 하자는 회의가 있었고, 이것을 권고사항으로 SCOR에 보고하여 1968년 11월에 ICES가 승인하므로써 Intercalibration에 관한 원칙이 정해졌다. 동시에 Finland의 Koroleff씨와 Palmork씨가 organizer로 정해졌던 것이다. 이 보다 약간 앞서 본인이 상모중연에 가 있을 때 Std. Solution으로서 아질산염용액 만으로 각종무기질소화합물의 표준용액으로 대용한다는 것은 비합리적이므로 질산염과 암모늄염의 표준용액이 있어야 한다고 주장하여 우선 질산염용액을 추가로 만들기로 하여 1968년 11월부터 표준물질의 정제부터 시작 되었다. 1969년 1월에 Intercalibration 에 관한 구체적인 회의를 위해 Scripps 해양연구소에 관원, Wooster Rakestraw, Cieskes씨등이 모여 우선 일본상모중연에서 만들고 있는 인산염, 질산염, 아질산염, 규산염의 CSK 표준용액을 표준시료로하여 SCOR 과 ICES의 해양화학분과에서 선정한 세계 100개처에 나누어 현재 각자가 사용하고 있는 방법의 정밀도와 정확도를 check하는 소위 International intercalibration을 1969년 9월부터 시작하기로 확정을 보았고, 동시에 구체적인 지시가 있었던 것이다. 이시료를 받는 사람에게는 다만 그것의 농도범위만 알려주고 정확한 농도는 Koreleff와 관원씨만이 알고 있기로 하여 측정에 분석자의 주관이 개입되지 못하도록 했고, 분석치는 SCOR가 모아 해석하되 번호제로 하여 어떤 나라의 누구가 했다는 것은 밝히지 않기로 되어 있다. 이같은 내력으로 CSK Std. Solution이 국제적인 Intercalibration용의 표준시료로서 시험적으로 사용되기 까지는 되었으나, CSK Std. Solution 그자체에 관해서는 아직도 해결해야 할 점, 개량을 요하는 점이 많다. 이하에서는 주로 개량을 요하는 점에 관해 몇가지 언급하고자 한다.

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Two anthozoans, Entacmaea quadricolor (order Actiniaria) and Alveopora japonica (order Scleractinia), host consistent genotypes of Symbiodinium spp. across geographic ranges in the northwestern Pacific Ocean

  • Chang, Soo-Jung;Rodriguez-Lanetty, Mauricio;Yanagi, Kensuke;Nojima, Satoshi;Song, Jun-Im
    • Animal cells and systems
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    • v.15 no.4
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    • pp.315-324
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    • 2011
  • The actiniarian sea anemone, Entacmaea quadricolor, and the scleractinian coral, Alveopora japonica, host symbiotic dinoflagellates belonging to the genus Symbiodinium (Freudenthal). We studied the host-symbiont specificity of these two anthozoan hosts in the northwestern Pacific Ocean. Symbionts within the two hosts were identified using partial large subunit (LSU) ribosomal DNA (rDNA) and complete internal transcribed spacers (ITS) 1 rDNA regions. The host, E. quadricolor, was identified using the partial LSU rDNA molecular marker. Genetic analysis showed that E. quadricolor only harbors dinoflagellates belonging to subclade C1/3 of the genus Symbiodinium. Moreover, no genetic variation was detected among the symbionts of E. quadricolor within the study region (Korea and Japan), even though the two distant sites were separated by more than 1000 km, at collection depths of 1 m in shallow and 13-16 m in deep water. Whilst scleractinian corals host multiple Symbiodinium clades in tropical waters, A. japonica, sampled over a wide geographical range (800 km) within the study region, only hosts Symbiodinium sp. clade F3. The high specificity of endosymbionts in E. quadricolor and A. japonica within the northwestern Pacific Ocean could be accounted for because symbiotic dinoflagellates within the host anemones appear to be acquired maternally, and the Kuroshio Current might affect the marine biota of the northwestern Pacific. However, the consistency of the symbiotic relationships between these two anthozoan hosts and their endosymbionts could change after climate change, so this symbiotic specificity should be monitored.

Climate change and fluctuations of pelagic fish populations in the Far East region

  • Gong, Yeong;Suh, Young-Sang
    • Journal of Ecology and Environment
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    • v.35 no.1
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    • pp.15-25
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    • 2012
  • Time series of ocean climate indices and catch records were used to identify the alternation patterns of pelagic fish populations in relation to climate regime shifts. During 1910-2008, an orderly alternation of dominant pelagic fish groups was observed in the Tsushima Warm Current (TWC; Yellow Sea-East China Sea-East Sea/Japan Sea) and Kuroshio-Oyashio Current (KOC; Northwestern Pacific) regions. After the collapse of herring fishery in the late 1920s, the sardine (A group) dominated in the 1930s, 3 other species (C group; Pacific saury, jack mackerel, and anchovy) dominated in the 1950s-1960s, chub mackerel (B group) dominated in the 1970s, and then sardine (A group) dominated again during cool regime in the 1980s. As sardine biomass decreased in association with the climate regime shift that occurred in the late 1980s, catches of C group immediately increased after the regime shift and remained at high levels during warm regime in the 1990s. Alternations of dominant fish groups occurred 6 times between 1910 and 2008. The dominant period of the 7 species lasted for 10-20 years. The catch of Pacific sardine in the TWC and KOC regions showed a negative correlation with the catch of the other 5 species (Pacific herring, anchovy, jack mackerel, Pacific saury, and common squid), suggesting that the abundance of the 5 species is strongly affected by the abundance of Pacific sardine in relation to the climate regime shifts. The total catch level of the 7 species in the KOC region was generally higher than that in the TWC region before 1991 but was lower after 1992, suggesting that the fish populations in the Pacific side are shifted to the TWC region by zonal oscillation of the oceanic conditions in relation to the climate regime shift in the late 1980s.

Zoogeography of Taiwanese Fishes

  • Nakabo, Tetsuji
    • Korean Journal of Ichthyology
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    • v.21 no.4
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    • pp.311-321
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    • 2009
  • Three categories (freshwater, amphidromous, and marine fishes) of Taiwanese fishes are analyzed on the basis of zoogeographic elements, viz. China element, Indo-China element, Indo-West Pacific element, Indo-Pacific element, North-Pacific element, Japan-Oregon element, and circumtropical element. Freshwater fishes, which include the China and Indo-China elements, are distributed on part of the boundary area between the Palaearctic and Oriental regions of Wallace (1876). Diadromous fishes include the North-Pacific, Indo-China and Indo-West Pacific elements. Taiwanese salmon, a landlocked (initially diadromous) species that became established in Taiwan between 0.5 my B.P. and the early Pleistocene, is recognized as a distinct taxon included within the Oncorhynchus masou complex, which comprises here three species and two subspecies, viz. Oncorhynchus masou masou (Sancheoneo, Songeo, Sakura-masu or Yamame), O. masou ishikawae (Satsuki-masu or Amago), O. sp. (Biwa-masu), and O. formosanus (Taiwanese salmon), based on molecular, morphological and biological studies. Marine fishes are discussed under the following headings, brackish-water fishes (fishes of brackish waters and seas adjacent to continental coastlines, North Pacific and Indo-West Pacific elements; fishes of brackish waters and seas primarily around islands, Indo-West Pacific element), reef fishes (fishes of inshore reefs along continental coastlines from 0 to ca.100 m depth, Indo-West Pacific element; fishes of inshore reefs primarily around islands from 0 to ca.100 m depth, Indo-West Pacific element; fishes of offshore reefs along continental shelf edges from ca.150 to 300 m depth, circumtropical and Indo-Pacific elements; fishes of offshore reefs primarily around islands from ca.150 to 300 m depth, Indo-Pacific element), demersal fishes (fishes on continental shelves shallower than ca.150 m depth, Indo-West Pacific and Japan-Oregon elements; fishes on edges and upper continental slopes from ca.150 m to 500 m depth, Indo-West Pacific, Indo-Pacific, and circumtropical elements; fishes on lower continental slopes to abyssal plains from ca.500 m to 6,000 m depth, circumtropical element and rarely Indo-Pacific element), pelagic fishes (epipelagic fishes from 0 to ca.150 m depth, Indo-West Pacific, Indo-Pacific or circumtropical elements; meso- and bathypelagic fishes from ca.150 to 3,000 m depth, circumtropical element). The distribution of Taiwanese marine fishes are influenced by the Kuroshio Current, low-salinity and low-temperature waters from mainland China, and sea-bottom topography.