• Ocean Science Journal
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• 제41권4호
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• pp.227-234
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• 2006

Year-to-year variation of bottom cold waters around the Korea Strait was investigated based on bottom temperatures measured by submarine telephone cable between Pusan, Korea and Hamada, Japan from 1982 to 1992. The characteristics of bottom temperatures could be divided into three different groups: the Korean side, the middle, and the Japanese side. Temperature drops in summer appeared in all the three regions implying the intrusion of cold waters into the Korea Strait. Significant decreases in the Korean side were observed in 1983, 1986, 1990, 1991, and 1992 when bottom temperatures were high in the middle. In contrast, bottom temperatures significantly decreased in the middle in 1985, 1988, and 1989 when the temperature drops in the Korean side were relatively small. This tendency for a negative relationship was also shown in the second mode of an EOF analysis. In the years when bottom temperatures significantly decrease din the Korean side, the cold water along the east coast of Korea expanded offshore and its temperature was low. On the contrary, cold water in the southern region of the Ulleung Basin developed in the years when bottom temperatures decreased considerably in the middle.

• Ocean Science Journal
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• 제41권4호
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• pp.291-299
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• 2006

Hydrographic surveys were carried out four times in the western channel of the Korea Strait in March and August 2003 and in June and November 2004. The bottom cold water, which was lower than $10^{\circ}C$, appeared in the channel trough except in March 2003. It flowed southwestward along the shelf of Korean coasts in August 2003 and in November 2004. The width and the maximum speed of the intrusion current were about 20 km and approximately $25\;cm\;s^{-1}$, respectively, off Ulsan, Korea. The volume transport of the bottom cold water was estimated 0.019 Sv ($Sv{\equiv}10^6\;m^3\;s^{-1}$) in August 2003 and 0.026 Sv in November 2004.

• 한국해양학회지
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• 제29권4호
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• pp.414-421
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• 1994

여름철 남해 중앙해역 저층에는 14$^{\circ}C$ 이하의 저온수가 남해에서 관측된 기존의 수 온 염분 자료를 분석하여 이 저온수의 특성과 기원에 대하여 알아. 6월과 8월에 저온 수의 염분은 33.4~34.0$\textperthousand$로 4월에 비해 약 0.6$\textperthousand$ 낮으며, 특히 1983년에는 6월부터 8 월에 더 저온인 해수가 나타났다. 이와 같은 현상들은 여름철 남해의 저온수는 겨울에 형성되어 여름까지 잔류한 것이 아니고 주위해역에서 유입된 해수임을 시사한다. 이 저온수는 14$^{\circ}C$ 이하 저온수의 출현빈도분포와 제주해협 부근에서 관측된 수온 염분 자 료 분석 등에 의해 제주해협 서편해역에서 남해로 유입되는 것으로 추정된다.

• 한국항해학회지
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• 제21권4호
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• pp.39-47
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• 1997

We researched the mechanism on th flucturain of Bottom Cold Water in the western channel of Korea Strait, using 13 years(1981~1933) oceanographic data of FRDA. The bottom cold water in the western channel appears more often in summer and fall than in winter and spring, and its year-to-year variation of temperature is very large. Such variation seems to be closely related with the variations of cold waters in the subsurface layer of the southwestern East Sea. According to the longitudinal temperature distribution along the korean southeastern coast, a density difference occurs all the time at the still deepth between the western channel and the southwestern East Sea. Thus, it is inferred that the cold waters would intrude into the western channle form the subsurface layer in the southwestern East Sea as a density-driven current, and it intensity depends upon the density difference.

• 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).

• 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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• 제33권4호
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• pp.196-204
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• 1998

$^{14}$C uptake experiments were carried out in and around the cold water mass in the southern part of the Korean East Sea in August and October 1995 to assess spatial and seasonal variability of primary productivity and its relation to physical and chemical factors. The cold and high saline water mass in the bottom layer extended upward to the surface layer and developed along the eastern coast of Korea in August. Chlorophyll-a concentration was maintained high in the cold water mass through August to October and its maximum concentration was 6.3 ${\mu}$g 1$^{-1}$ at Stn. 209-4 in August. Primary productivity and daily primary productivity ranged from 0.29 to 8.02 mgC m$^{-3}$ hr$^{-1}$ and from 58.3 to 63.1 mgC m$^{-2}$ d$^{-1}$, respectively, throughout the study period. Primary productivity of the cold water mass was higher than that of offshore waters in both summer and autumn seasons. P$_{max}$ and I$_{max}$ of the cold water mass in August were higher than those in October, except Stn. 208-5. These results suggest that high primary productivity in the cold water mass may be established by the upwelled nutrients and light adaptaion to convected phytoplankton due to upwelling of the bottom waters.

• 한국수산과학회지
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• 제49권3호
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• pp.393-403
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• 2016

A steady, strong southward flow was observed in the lower layer beneath the Tsushima Warm Current in the deepest trough of the Korea Strait. Known as the Korea Strait Bottom Cold Water (KSBCW), this bottom current had a mean velocity of 24 cm/s and temperatures below 8–10℃. The direction of the bottom current was highly stable due to the topographic effects of the elongated trough. To determine the path of the southward bottom current, ADCP (Acoustic Doppler Current Profiler) data from 14 stations between 1999 and 2005 were examined. Persistent southward flows with average speeds of 4–10 cm/s were observed at only three places to the north of the strait where the bottom depths were 100–124 m. The collected data suggest a possible course of the southward bottom current along the southeast Korean coast before entering the deep trough of the Strait.

• Journal of the korean society of oceanography
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• 제38권3호
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• pp.87-100
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• 2003

The monthly observations of hydrography in the Cheju Strait from September 1995 to June 1998 show that the Cheju Strait is occupied mostly by Tsushima Current Water in winter and coastal waters in summer. In summer, the Yangtze Coastal Water appears in the upper layer and cold water in the lower layer. Especially, the Yellow Sea Bottom Cold Water appears in August 1997, and the clockwise flow of warm water along the northwestern coasts of Cheju Island is disturbed by an eastward expansion of the cold water from the northwest. The cold water expansion seems to be partly associated with strong southeasterly winds. Current measurements in the Cheju Strait suggest that there exists steady eastward barotropic component of about 5 cm/sec, which corresponds to 0.2 Sv barotropic transport in the Cheju Strait. Geostropic transport (baroclinic component) ranges from 0.1 Sv in winter to 0.4 Sv in summer. By adding the barotrophic component of 0.2 Sv, the total transport varies from 0.3 Sv to 0.6 Sv, which is consistent with previous estimations. The transport increase in summer seems to be caused by the expansion of coastal water to the Cheju Strait.

• 한국수산과학회지
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• 제25권1호
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• pp.1-14
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• 1992

국립수산진흥원의 16개년(1973-1988)의 해양 관측 자료와 1989년 11월 6-11일 동안 한국해양대학 실습선으로 관측한 CTD 자료를 사용하여 대한해협 서수도에 존재하는 저층 냉수의 유입 경로를 조사하였다. 대한해협 서수도의 저층 수온은 하계에 가장 낮으며, 해에 따라 변동이 큰 것으로 나타났다. 하계 대한해협 서수도에 저층 냉수가 존재하였던 해의 수온 분포에 의하면, 동해 남서부 해역에 있는 냉수가 울산 남동쪽 10-15마일 떨어진 해역을 거쳐 대한해협 서수도에 유입되며, 이 냉수는 이류하는 동안 그 특성이 다소 변하는 것으로 나타났다.