• Journal of the korean society of oceanography
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• 제39권1호
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• pp.1-13
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• 2004

The Yellow Sea Warm Current (YSWC) and the Yellow Sea Cold Bottom Water (YSCBW) are two protruding features, which have strong influence on the community structure and distribution of zooplankton in the Yellow Sea. Both of them are seasonal phenomena. In winter, strong north wind drives southward flow at the surface along both Chinese and Korean coasts, which is compensated by a northward flow along the Yellow Sea Trough. That is the YSWC. It advects warmer and saltier water from the East China Sea into the southern Yellow Sea and changes the zooplankton community structure greatly in winter. During a cruise after onset of the winter monsoon in November 2001 in the southern Yellow Sea, 71 zooplankton species were identified, among which 39 species were tropical, accounting for 54.9 %, much more than those found in summer. Many of them were typical for Kuroshio water, e.g. Eucalanus subtenuis, Rhincalanus cornutus, Pareuchaeta russelli, Lucicutia flavicornis, and Euphausia diomedeae etc. 26 species were warm-temperate accounting for 36.6% and 6 temperate 8.5%. The distribution pattern of the warm water species clearly showed the impact of the YSWC and demonstrated that the intrusion of warmer and saltier water happened beneath the surface northwards along the Yellow Sea Trough. The YSCBW is a bottom pool of the remnant Yellow Sea Winter Water resulting from summer stratification and occupy most of the deep area of the Yellow Sea. The temperature of YSCBW temperature remains ${\leq}{\;}10^{\circ}C$ in mid-summer. It is served as an oversummering site for many temperate species, like Calanus sinicus and Euphaisia pacifica. Calanus sinicus is a dominant copepod in the Yellow Sea and East China Sea and can be found throughout the year with the year maximum in May to June. In summer it disappears in the coastal area and in the upper layer of central area due to the high temperature and shrinks its distribution into YSCBW.

• Ocean and Polar Research
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• 제26권1호
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• pp.65-75
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• 2004

In order to understand the water masses and their distribution in the eastern Yellow Sea from winter to spring, a cluster analysis was applied to the temperature and salinity data of Korea Oceanographic Data Center from 1970 to 1990. From December to April, Yellow Sea Cold Water (YSCW) dominates the eastern Yellow Sea, whereas Eastern Yellow Sea Mixed Water (MW) and Yellow Sea Warm Water (YSWW) are found in the southern part of the eastern Yellow Sea. MW appears at the frontal region around $34^{\circ}N$ between YSCW in the north and YSWW in the south. On the other hand, Tshushima Warm Water (TWW) is found around Jeju Island and the South Sea of Korea. These water masses are relatively well-mixed throughout the water column due to the winter monsoon. However, the water column begins to be stratified in spring due to increased solar heating, the diminishing winds and fresh water discharge, and the water masses in June may be separated into surface, intermediate and bottom layers of the water column. YSWW advances northwestward from December to February and retreats southeastward from February to April. This suggests a periodic movement of water masses in the southern part of the eastern Yellow Sea from winter to spring. YSWW may continue to move eastward with the prevailing eastward current to the South Sea from April to June. Also, the front relaxes in June, but the mixed water advances to the north, increasing salinity. The salinity is also higher in the nearshore region than offshore. This indicates an influx of oceanic water to the north in the nearshore region of the eastern Yellow Sea in spring in the form of mixed water.

• Journal of the korean society of oceanography
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• 제37권3호
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• pp.187-195
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• 2002

The characteristics of surface circulation in the Yellow Sea and the East China Sea are discussed by analyzing a great deal of current data observed by 142 sets of mooring buoy and 58 sets of drifters trajectories collected in the Yellow Sea and the East China Sea through domestic and abroad measurements. Some major features are demonstrated as bellow: 1) Tsushima Warm Current flows away from the Kuroshio and has multiple sources in warm half year and comes only from Kuroshio surface water in cold half year. 2) Taiwan Warm Current comes mainly from the Taiwan Strait Water in warm half year and comes from the intruded Kuroshio surface water and branches near 27N in cold half year. 3) The Changjiang Diluted Water turns towards Cheju Island in summer and flows southward along the coastal line in winter. 4) The study sea area is an eddy developing area, especially in the southern area of Cheju Island and northern area of Taiwan.

• Journal of the korean society of oceanography
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• 제33권3호
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• pp.41-52
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• 1998

A seasonal circulation pattern in the eastern Yellow Sea (EYS) is suggested from the water mass analysis and geostrophic calculation using the hydrographic data collected by National Fisheries Research and Development Institute during the years of 1970 to 1990. This research focuses on the presence of inflow of warm (and saline) waters into EYS in summer. EYS is divided into two regions in this paper: the west coast of Korea (WCK) and the central Yellow Sea (CYS). In CYS, waters are linked with warm waters near Cheju Island in winter, but with cold waters from the north in summer (in the lower layer). It is not simple to say about WCK because of the influences of freshwater input and tidal mixing. Nevertheless, water mass analysis reveals that along WCK, waters have the major mixing ratios (40-60%) of warm waters in summer, while the dominant mixing ratios (50-90%) of cold waters in winter. Such a seasonal change of water mass distribution can be explained only by seasonal circulation. In winter, warm waters flow northward into CYS and cold waters flow southward along WCK. In summer, warm waters flow northward along WCK and cold waters flow southward into CYS. This circulation pattern is supported by both statistical analysis and dynamic depth topography. Accordingly, Yellow Sea Warm Current may be defined as the inflow of warm waters to CYS in winter and to WCK in summer.

• 한국해양학회지:바다
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• 제8권3호
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• pp.327-339
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• 2003

겨울철인 1998년 2월과 1999년 1월, 4월에 남해와 동중국해 북부해역에서 형성되는 전선의 분포와 구조를 파악하기 위하여 광역의 종합해양관측을 수행하였다. 관측해역에서 구분된 수계들은 대마난류기원 고온수, 황해냉수(북부냉수 혹은 중앙냉수) 그리고 남해저온수로 분류된다. 황해남부 해역에서는 제주도 서쪽을 우회하여 제주해협으로 유입하는 대마난류기원 고온수가 '┍'자 형태의 기본적 전선을 이루며 대흑산도 남쪽에 황해중앙냉수와 그리고 양자천퇴 동부에서 황해북부냉수와 만나고 있다. 이 전선은 고온수가 황해 북서부로 확장하는 세기에 의해 전선 모서리 형태와 위치가 달라진다. 양자천퇴 부근과 한반도 남서단 외측에서의 전선위치와 구조도 관측시기에 따라 변화한다 남해 전선에서는 연안 저온수가 국지적 냉각에 의해 독립적으로 형성된 수계로서 해저사면을 따라 침강한다. 이러한 겨울철 전선분포의 변화와 전선구조가 변화되는 과정은 탁월풍에 의한 순풍류 및 역풍류, 해수면을 통한 열수지 그리고 전선사이의 밀도차이에 의한 것으로 설명되었다.

• 한국수산과학회지
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• 제47권4호
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• pp.419-423
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• 2014

We consider changes in the fishing ground of the small yellow croaker Larimichthys polyactis and discuss their utility in predicting fishing conditions for this species. The fishing ground, which having been formed around Jeju Island since the 1970s, is dominated by the Yellow Sea Bottom Cold Water (YSBCW), and variation in its southward expansion from the Yellow Sea is the single most key environmental factor affecting the L. polyactis catch. When the YSBCW showed strong expansion and the fishing ground shifted to the west and southwest of Jeju Island, as occurred in the late 1980s, late 1990s, and early 2000s, the L. polyactis catch was low; conversely, when expansion was weak, as in the early 1990s and late 2000s, the L. polyactis catch was high. This relationship was statistically significant and should be useful in predicting fishing conditions for L. polyactis.

• 한국수산과학회지
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• 제50권6호
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• pp.818-823
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• 2017

The diet composition of juvenile gold-eye rockfish, Sebastes thompsoni (40-50 mm SL), was examined based on 121 individuals collected in the Yellow Sea Bottom Cold Water in August 2016. The Yellow Sea Bottom Cold Water is characterized a by water mass of <$10.0^{\circ}C$ and 33 psu. The juvenile gold-eye rockfish fed on Amphipods [57.3% index of relative importance (IRI)] and Euphausiacea (32.9%). Most of the point in the prey-specific abundance plot indicated a high between-phenotype component (BPC).

• Ocean Science Journal
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• 제43권2호
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• pp.67-79
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• 2008

We investigated the relationship between mesoscale spatial distribution of environmental parameters (temperature, salinity, and sigma-t), chlorophyll-a concentration and mesozooplankton in the Yellow Sea during May 1996, 1997, and 1998, with special reference to Yellow Sea Bottom Cold Water (YSBCW). Adult calanoid copepods, Calanus sinicus, Paracalanus parvus s.l., Acartia omorii, and Centropages abdominalis were isolated by BVSTEP analysis based on the consistent explainable percentage (-32.3%) of the total mesozooplankton distributional pattern. The copepods, which accounted for 60 to 87% of the total abundances, occupied 73-78% of the copepod community. The YSBCW consistently remained in the northern part of the study area and influenced the spatial distribution of the calanoid copepods during the study periods. Abundances of C. sinicus and P. parvus s.l., which were high outside the YSBCW, were positively correlated with the whole water average temperature (p<0.01). In contrast, the abundances of C. abdominalis and A. omorii, which were relatively high in the YSBCW, were associated with the integrated chl-a concentration based on factor analysis. These results indicate that the YSBCW influenced the mesoscale spatial heterogeneity of average temperature and integrated chl-a concentration through the water column. This consequently affected the spatial distribution pattern of the dominant copepods in association with their respective preferences for environmental and biological parameters in the Yellow Sea during spring.

• 수산해양교육연구
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• 제23권3호
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• pp.425-432
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• 2011

하계와 추계사이 황해저층냉수괴의 분포양상과 영양염 특성을 파악하기 위하여 2006년 9월에 황해 내 15개 정점에서 수온, 염분, 영양염류 등을 조사하였다. 9월에 연구해역의 표층수는 $20^{\circ}C$ 이상을 나타내는 양자강 희석수가 분포하고, 30m이심층에서는 $10^{\circ}C$ 이하의 냉수괴가 분포하였다. 특히 50m이심층에서는 $8^{\circ}C$ 이하의 수괴가 북위 $35^{\circ}$까지 남하하고 있었으며 조사정점에서 우리나라 연안쪽보다는 중국연안쪽에 확장되고 있음을 나타내고 있었다. $8^{\circ}C$의 냉수괴가 분포하는 50m이심층에서의 염분은 33.5psu로 상대적으로 높게 분포하며 북쪽으로 밀려 올라가고 있는 형상으로 수온, 염분 전선역이 형성되고 있음을 보여주고 있다. 영양염류 등 총무기질소 농도분포는 냉수괴에서 표층수보다 2배 이상 높은 농도를 보여 저층에서 저온현상에 의한 난분해와 소모가 낮음을 보여주고 있다. 결과적으로 9월까지 지층냉수괴는 북위 $35^{\circ}$까지 남하하고 있으며 냉수괴 내 높은 영양염 농도를 함유하고 있었다.

• Journal of the korean society of oceanography
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• 제39권1호
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• pp.72-95
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• 2004

The Yellow Sea is characterized by relatively shallow water depth, varying range of tidal action and very complex coastal geometry such as islands, bays, peninsulas, tidal flats, shoals etc. The dynamic system is controlled by tides, regional winds, river discharge, and interaction with the Kuroshio. The circulation, water mass properties and their variability in the Yellow Sea are very complicated and still far from clear understanding. In this study, an effort to improve our understanding the dynamic feature of the Yellow Sea system was conducted using numerical simulation with the ROMS model, applying climatologic forcing such as winds, heat flux and fresh water precipitation. The inter-annual variability of general circulation and thermohaline structure throughout the year has been obtained, which has been compared with observational data sets. The simulated horizontal distribution and vertical cross-sectional structures of temperature and salinity show a good agreement with the observational data indicating significantly the water masses such as Yellow Sea Warm Water, Yellow Sea Bottom Cold Water, Changjiang River Diluted Water and other sporadically observed coastal waters around the Yellow Sea. The tidal effects on circulation and dynamic features such as coastal tidal fronts and coastal mixing are predominant in the Yellow Sea. Hence the tidal effects on those dynamic features are dealt in the accompanying paper (Kim et at., 2004). The ROMS model adopts curvilinear grid with horizontal resolution of 35 km and 20 vertical grid spacing confirming to relatively realistic bottom topography. The model was initialized with the LEVITUS climatologic data and forced by the monthly mean air-sea fluxes of momentum, heat and fresh water derived from COADS. On the open boundaries, climatological temperature and salinity are nudged every 20 days for data assimilation to stabilize the modeling implementation. This study demonstrates a Yellow Sea version of Atlantic Basin experiment conducted by Haidvogel et al. (2000) experiment that the ROMS simulates the dynamic variability of temperature, salinity, and velocity fields in the ocean. However the present study has been improved to deal with the large river system, open boundary nudging process and further with combination of the tidal forcing that is a significant feature in the Yellow Sea.