• 한국해양학회지
• /
• v.27 no.4
• /
• pp.259-267
• /
• 1992

A survey of CTD casting was taken in April 1991 in the eastern Yellow Sea. The vertical structure of water column consists of the upper mixed warm, the mid cold and the lower warm layers devised clearly by a seasonal thermocline and the temperature inversion. A strongest temperature inversion is found in the southern part of the survey area. Where the low-layer water is $3^{\circ}C$ higher than the mid-layer water. The area of the temperature inversion covers about $100{\;}km{\;}{\times}{\;}100{\;}km$ and it is observed 1.5 month later. The temperature and salinity of the low-layer water shows a core structure in vertical sections and the tongue-like distribution extending from the south to the north, implying that the warm and saline water found in the oceanic front south of the survey area in early spring is advocated to the north over 150 km underneath the Yellow Sea cold water.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.28 no.1
• /
• pp.19-40
• /
• 2023

To investigate the role of water masses in the Jeju Strait in summer on the shallow coastal region and the characteristics of water properties in the strait, temperature and salinity were observed across the Jeju Strait in June, July, and August 2019. The cold water pool, whose temperature is lower than 15℃, was observed in the mid-depths of the central Jeju Strait and on the northern bottom slope of the strait. The cold water pools have the lowest temperature in the strait. To identify water masses comprising the cold water pool in the Jeju Strait, mixing ratios of water masses were calculated. The mid-depth cold water pool of the Jeju Strait consists of 54% of the Kuroshio Subsurface Water (KSSW) and 33% of the Yellow Sea Bottom Cold Water (YSBCW). Although the cold water pool is dominantly affected by the KSSW, the YSBCW plays a major role to make the cold water pool maintain the lowest temperature in the Jeju Strait. To find origin of the cold water pool, temperature and salinity data from the Yellow Sea, East China Sea, and Korea Strait in the summer of 2019 were analyzed. The cold water pool was generated along the thermohaline frontal zone between the KSSW and YSBCW in the East China Sea where intrusion and mixing of water masses are active below the seasonal thermocline. The cold water in the thermohaline frontal zone had similar mixing ratio to the cold water pool in the Jeju Strait and it advected toward the Korea Strait and shallow coastal region off the south coast of Korea. Intrusion of the mid-depth cold water pool made temperature inversion in the Jeju Strait and affected sea surface temperature variations at the coastal region off the south coast of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.24 no.3
• /
• pp.177-184
• /
• 1991

We have investigated geographical distribution and physico-chemical properties of water masses or water types at mid-bottom depth in the neighbouring sea of Cheju Island in August 1986. In 50m layer the Yellow Sea Bottom Cold Water(YSBCW) below $12^{\circ}C$ was observed in the northwestern area of Cheju Island, while the Tsushima Warm Water(TWW) with relatively high temperature$(>16^{\circ}C)$ and salinity more than 34.0 in its southeastern area extended as far as the coast of about 15km. Also, 50m layer at the outside stations of its southwestern area indicated relatively cold water temperature$(11-30^{\circ}C)$, probably due to southward transport of the Yellow Sea Bottom Cold Water(YSBCW . The Yellow Sea Warm Water(YSWW), the mixed water of the YSBCW and the TWW, ranged $13^{\circ}C$ to $16^{\circ}C$ in water temperature and was appeared mainly in the coastal and intermediate area of Cheju Island. And the relatively cold water in the southwestern area and the Tsushima Warm Water were more extensively distributed in 50m layer than the deeper layer. Horizontal distributions of nitrate and phosphate showed a pattern similar to that of water temperature. As it were, the Yellow Sea Bottom Cold Water had the highest concentration of nutrients, while southwestern outside stations had the lowest nutrient contents. Especially, the concentration of nitrate in the latter was remarkably low compared with the value at the other stations. It may be attributed to intensive vertical mixing by collision of the northward driven Tn with the southward driven YSBCW. Also, it was particular that the Tsushima Warm Water indicated relatively high silicate content corresponding to that of the Yellow Sea Bottom Cold Water. Based on the data of $\Delta Si/\Delta P$ ratio, it seems that the mid-bottom waters in this study area are younger than the surface or intermediate water in the Korean East Sea.

• Journal of Fisheries and Marine Sciences Education
• /
• v.23 no.3
• /
• pp.425-432
• /
• 2011

In order to understand the characteristics of the distribution and the nutrients of the Yellow Sea Bottom Cold Water during summer to fall, temperature, salinity and nutrients have been investigated in the fifteen stations in the Yellow Sea. In september, the Changjiang diluted water with more than $20^{\circ}C$ distributed in the surface and the Yellow Sea Bottom Cold Water distributed in the layer below 30m depth with less than $10^{\circ}C$. Specially, water mass with less than $5^{\circ}C$ in the layer below 50m depth expanded southward down to the north latitude of $35^{\circ}$ with expanding more to the coasts of China than to the coasts of Korea. The salinity of the cold water mass with $8^{\circ}C$ in the deep layer of more than 50m depth was relatively high as 33.5 psu and expanded northward forming fronts of temperature and salinity. The concentration of total inorganic nitrogen was two times higher in the cold water mass than in the surface water, which means that resolution and consumption were low due to cold temperature in the bottom layer. In conclusion, the cold water expanded southward down to the north latitude of $35^{\circ}$ by September and had high concentration of nutrients.

• 한국해양학회지
• /
• v.30 no.5
• /
• pp.442-457
• /
• 1995

The relationships of environmental factors to the distribution patterns of the three species of ophiuroids, Ophiura kinbergi, O. sarsi and ). sarsi vadicola from Yellow Sea southeast seas and East Sea of Korea were studied to characterize their habitual niches. These three species chosen for study illustrated distinct niche and patterns according to their various preferences mainly for bottom water temperature, bottom water salinity and depth from seven environmental variables which were depth, bottom water temperature and salinity, density, bottom water oxygen content, grain size of the surface sediment, and sediment sorting coefficient. The results of habitat niche study mainly dealing with O. sarsi vadicola suggested that the optimum habitat rages were approximately 6$^{\circ}C$∼10$^{\circ}C$ in bottom temperature and 31%∼33.5% in bottom water salinity which also corresponded with the characteristic ranges of Yellow Sea Bottom Cold Water and higher probabilities of occurrence (more than 70%) were found in depth ranging from 100 to 200 m. In addition, the habitats of O. kinbergi and O. sarsi were compared with that of O. sarsi vadicola. Their ranges of habitat niches were found to have different niches in physical space of bottom water temperature, bottom water salinity and depth. Based on the distribution pattern of O. sarsi vadicola in the Yellow Sea, the ecological barrier which confined the distribution of benthic macro-invertebrates in southern Yellow Sea was determined to be the Yellow Sea Warm Current (approximately 34% < and 18$^{\circ}C$ in December) which occurs between 33$^{\circ}$ and 34$^{\circ}$N of southern Yellow Sea in winter time.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.18 no.1
• /
• pp.25-33
• /
• 1982

The secular fluctuations of catches and fishing grounds and their relations to the bottom temperature are examined by using data of catches of the Yellow Croaker and the Kang-dal-li by stow net in the Yellow Sea and the East China Sea during recent ten years, 1970-1979. The phase of the secular fluctuations of the catches was delayed about two years to that of during 1974-1975, and thereafter were balanced up to the end of 1976. However, after 1976, such tendency was not distinct because of an increase in fishing efforts. The fishing ground in 1977, in which temperatures were lower than other years, was found in the southern part of the fishing grounds of warmer years, for example, 1972.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.18 no.2
• /
• pp.81-89
• /
• 1982

In order to analyze the formation mechanism for the fishing ground of the Gang-dal-i, the relationship between the fish grounds of the Gang-dal-i and the oceanographic structure of the East China Sea and the Yellow Sea is investigated by using the data of the catches of stow net fishery (Fisheries Research and Development Agency, 1970-1979) and the oceanographic observation data (Japan Meteorological Agency). The main fishing grounds of the Gang-dal-i concentrated in the adjacent seas of Daeheugsan island and Sokotra Rock. In these areas, the fishing conditions are generally stable, because about 70% of the total catch of the Gang-dal-i for the ten years is occupied, CPUE also is relatively great, and the coefficients of variation of the catches are relatively small as 0.9 to 1.4. The main fishing periods are roughly from February to March and June to July, and the years of good catches are from 1974 to 1976. In general, the main fishing grounds are formed in the marginal areas of the Yellow Sea Bottom Cold Water. They are the frontal areas in which the Yellow Sea Bottom Cold Water is intermixed with the Yellow Sea Warm Current. The range of the temperature and the salinity in these regions are from 10 to 13$^{\circ}C$ and 32.5 to 34.4$\textperthousand$, respectively.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.10a
• /
• pp.200-201
• /
• 2001

제주도 연안 천해역 환경은 대마난류수, 한국남해연안수, 중국대륙연안수, 황해 저층냉수 등의 외해에 분포하고 있는 여러 수괴에 의해 영향을 받고 있지만 이외에도 제주도의 강수량, 기온, 북서계절풍 등과 같은 기상상태나 육수유입, 파랑, 조석상태 등에 의해서도 크게 영향을 받아 시ㆍ공간적 차가 생길 것으로 판단된다. (중략)

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.18 no.3
• /
• pp.189-206
• /
• 2015

The present study was conducted to investigate the oceanic characteristics of the northern East China Sea through identification of long-term variation patterns of oceanic environment factors, for the objective of gaining understanding of oceanic environment characteristics of the northern waters of East China Sea, which closely influence the oceanic environments of waters nearby South Korea. The study methodology included the use of oceanographic data (water temperature, salinity, dissolved oxygen, nutrients, and chlorophyll-a) on the northern East China Sea from the Korea Oceanographic Data Center (KODC), collected by season for 20 years between 1995 and 2014. Moreover, for the study on the distribution of nutrients, chlorophyll-a. The main water masses that affected the northern East China Sea during the study period were classified as Changjiang diluted water (CDW), Tiawan current warm water (TCWW), Yellow Sea cold water (YSCW), and Kuroshio source water (KW). The forces of CDW and TCWW that forms on the surface and sub-surface layers had weakened for 20 years and the force of KW that forms on the intermediate layer showed a distinctively decreasing trend. However, YSCW showed a trend of expanding its force. Phosphate and silicate exhibited a decreasing tendency and phosphate showed a pattern of being depleted on the surface layer after 2009. It is determined that one of the reasons for this is the concentration of nutrients introduced through CDW and TCWW being too low. The concentration of chlorophyll-a exhibited an increasing tendency during the study period, the reasons for which are determined to be the influences of increase in water temperature, supply of nutrients via YSCW, and increases in light transmission from decrease in suspended solid due to the construction of the Three Gorges Dam.

• 한국해양학회지
• /
• v.26 no.3
• /
• pp.262-277
• /
• 1991

Hydrographic data taken at stations spaced 8-16 nautical miles in the Cheju Strait and the southeastern part of the Yellow Sea in June 1980 and August 1981 show for the first time that oceanic water of high temperature and high salinity exists within 20 km from the northern and western coast of Cheju-Do. It is confirmed that the low salinity trough in the sea around Cheju-Do originates from the river plume on the Yantze Bank. The salinity trough separates the high temperature and high salinity water around Cheju-Do from the surface water of the Yellow Sea and below the seasonal thermocline this distance water meets the Yellow Sea Cold Water forming a thermal front. The Yellow Sea Cold Water seems to spread southward along the Yantze Bank centered at the isobath of 70 m. Its characteristics also appear in the northern part of the Cheju Strait. these complex structures contradict the yellow Sea Warm current suggested by Uda 1934), which is supposed to flow northward into the Yellow Sea along the western coast of Korea. Our data show that dense hydrographic surveys in space and time are prerequisite to understand the circulation around Cheju-Do.