• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.165-165
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• 2003

A borehole core ECSDP-102 (about 68.5 m long) has been investigated to get information on paleoenvironmental changes in response to the sea-level fluctuations during the period of late Quaternary. Several AMS $\^$14/C ages show that the core ECSDP-102 recorded the depositional environments of the northern East China Sea for approximately 60 ka. The Yangtze River discharged huge amounts of sediment into the northern East China Sea during the marine isotope stage (MIS) 3. In particular, $\delta$$\^$13/Corg values reveal that the sedimentary environments of the northern East China Sea, which is similar to the Holocene conditions, have taken place three times during the MIS 3. It is supported by the relatively enriched $\delta$$\^$13/Corg values of -23 to -21$\textperthousand$ during the marine settings of MIS 3 that are characterized by the predominance of marine organic matter akin to the Holocene. Furthermore, we investigated the three Holocene sediment cores, ECSDP-101, ECSDP-101 and YMGR-102, taken from the northern East China Sea off the mouth of the Yangtze River and from the southern Yellow Sea, respectively. Our study was focused primarily on the onset of the post-glacial marine transgression and the reconstructing of paleoenvironmental changes in the East China Sea and the Yellow Sea during the Holocene. AMS $\^$14/C ages indicate that the northern East China Sea and the southern Yellow Sea began to have been flooded at about 13.2 ka BP which is in agreement with the initial marine transgression of the central Yellow Sea (core CC-02). $\delta$$\^$18/O and $\delta$$\^$13/C records of benthic foraminifera Ammonia ketienziensis and $\delta$$\^$13/Corg values provide information on paleoenvironmental changes from brackish (estuarine) to modem marine conditions caused by globally rapid sea-level rise since the last deglaciation. Termination 1 (T1) ended at about 9.0-8.7 ka BP in the southern and central Yellow Sea, whereas T1 lasted until about 6.8 ka BP in the northern East China Sea. This time lag between the two seas indicates that the timing of the post-glacial marine transgression seems to have been primarily influenced by the bathymetry. The present marine regimes in the northern East China Sea and the whole Yellow Sea have been contemporaneously established at about 6.0 ka BP. This is strongly supported by remarkably changes in occurrence of benthic foraminiferal assemblages, $\delta$$\^$18/O and $\delta$$\^$13/C compositions of A. ketienziensis, TOC content and $\delta$$\^$13/Corg values. The $\delta$$\^$18/O values of A. ketienziensis show a distinct shift to heavier values of about 1$\textperthousand$ from the northern East China Sea through the southern to central Yellow Sea. The northward shift of $\^$18/O enrichment may reflect gradually decrease of the bottom water temperature in the northern East China Sea and the Yellow Sea.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.87-95
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• 2024

The giant jellyfish, Nemopilema nomurai, is an endemic species found in Northeast Asian waters and their population structures, such as size and genetics, and their environmental characteristics were investigated. N. nomurai was obtained from the Yellow and Northern East China Seas during the summers of 2006, 2007, and 2009. In the northern Yellow Sea, small-sized jellyfish were found to be dominant and towards the southern seas, the size of the jellyfish increased. In the northern East China Sea, only one mode of jellyfish was found in May, and the number of modes increased up-to five in July. However, at the center of the Yellow Sea, one or two modes were found in July, 2007. Thus, different jellyfish populations were present in the northern East China Sea and the Yellow Sea. However, based on first appearance and a cohort analysis using the bell diameter, the jellyfish population in the northern Yellow Sea might be recognized as a distinct group that differed from those found in the northern East China Sea. Furthermore, mitochondrial DNA sequences (cytochrome c oxidase subunit I) of N. nomurai were, determined and compared with genetic structures obtained from jellyfish in the Yellow Sea. The genetic diversity of N. nomurai was highest in the regions around the northern East China Sea and at the center of the Yellow Sea and was the lowest around the northern Yellow Sea. Thus, N. nomurai populations in the Yellow Sea and northern East China Sea might be different concerning their seeding places.

• Journal of the korean society of oceanography
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• v.35 no.4
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• pp.161-169
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• 2000

A seasonal circulation in the East China Sea and the Yellow Sea and its possible cause have been studied with CSK data during 1965-1989. Water mass distributions are clear in winter, but not in summer because the upper layer waters are quite influenced by atmosphere. To solve the problem, a water mass analysis by mixing ratio is used for the lower layer waters. The results show that the distribution of Tsushima Warm Current Water expands to the Yellow Sea in winter and retreats to the East China Sea in summer. It means that there is a very slow seasonal circulation between the East China Sea and the Yellow Sea: Tsushima Warm Current Water flows into the Yellow Sea in winter and coastal water flows out of the Yellow Sea in summer. By the circulation, the front between Tsushima Warm Current Water and coastal water moves toward the shelf break in summer so that the flow is faster in the deeper region. The process eventually makes the transport in the Korea Strait increase. The Kuroshio does not seem to influence the process. A possible mechanism of the process is the seasonal change of sea surface slope due to different local effects of surface heating and diluting between the East China Sea and the Yellow Sea.

• Journal of the korean society of oceanography
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• v.37 no.3
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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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• v.39 no.4
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• pp.212-221
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• 2004

Concentrations of suspended particulate matters (SPM) and their distribution patterns were monitored three times in the East China Sea during the winter season in 1998 and 1999. SPM concentrations showed significant temporal variations controlled by the atmospheric conditions and sea states. In coastal area, SPM values were about 10-20 mg/l in fair weather conditions, but exceeded 100mg/l during the storm periods. Turbid waters were distributed widespread in the continental shelf of the East China Sea and the coastal area of the Korean Peninsula, and these two areas were connected along a NE-SW direction. The distribution patterns of turbid waters were interpreted as representing the transport behavior of suspended matter. Although the primary source of inner shelf mud deposits of Korea seems to be the Korean Peninsula, contribution from the East China Sea to the coastal area of Korea increases especially during the winter season.

• Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.14-22
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• 2000

The relationship between the distribution of demersal fishes and that of the water masses was examined by using the catches data and hydrographic data in the Yellow Sea and the East China Sea on May 13-19, 1996 and May 10-17, 1997. During the study period, the dominant fish species were Cleisthenes pinetorum herzinsteini, Lophiomus setigerus and Pseudosciaena polyactis. These three low temperature water species accounted for $21-24\%$ of the total catches. The percentage of the low temperature water species was high in the Yellow Sea and the coastal area on the continental shelf of the East China Sea but was low in the vincinity of Kyushu during the study period. In the East China Sea, the isotherm of $15^{\circ}C$ at 50m, mid layer depth, was located more southeast in 1996 than in 1997. The bottom water temperature was about it lower in 1996 than in 1997. The direction of the detided current on the continental shelf of the East China Sea was southward in 1996 and northward in 1997. Yellow Sea Bottom Cold Water (YSBCW) strongly expanded to south in 1996 when the northward current was weak. But, Tsushima Warm Current (TSWC) strongly intruded into the continental shelf of the East China Sea in 1997. As YSBCW expanded strongly to south in 1996, the percentage of the low temperature water species relative to the total catches was high. But, TSWC strongly intruded and the percentage of low temperature water fishes was low in 1997.

• Journal of the korean society of oceanography
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• v.31 no.3
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• pp.123-133
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• 1996

We describe here the shallow water tides in the seas around Korea, obtained from a nonlinear barotropic model of tides in a domain encompassing the Yellow Sea, the East China Sea and the East Sea (Sea of Japan). As expected, the shallow water tides are large in the shallow marginal areas around the Yellow Sea, with the M4 tide reaching amplitudes as high as 10 cm near the Korean coast, and quite small in the East Sea. However, we also find that the regions east of the Yangtze River ($126^{\circ}E,$ $30^{\circ}N$) in the East China Sea also sustain large shallow water tides, with $M_{4}$, amplitudes reaching 5 cm. Such large shallow water tides are an important component of altimeter-measured sea levels and should not be ignored in any altimetric analyses of the Yellow Sea and the East China Sea. This study also highlights the desirability of very high resolution models to derive accurate shallow water tides in coastal regions.

• Water for future
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• v.16 no.4
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• pp.221-236
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• 1983

In semi-enclosed shallow sea areas typified by the Yellow sea and the East China Sea, currents and sea surface variations are predominantly tidal. During the recent years two-dimensional numerical hydrodynamic model of the Yellow Sea and the East China Sea has been developed, based on the vertically-integrated equations of motion and continuity, capable of reproducing amplitudes and phases of the principal components of tides to satisfiable accuracy. As a subsequent development a three-dimensional hydrodynamical nymerical model covering the Yellow Sea and the East China Sea has been formulated to investigate the vertical distribution of horizontal tidal current and the response of the continented to investigate the vertical distribution of horizontal tidal current and the response of the continental shelf sea to steady uniform wind stress field imposed over the surface. Features of the M2 tidal current and the wind-induced three-dimensional current structure determined from the computation have been examined and discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.243-258
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• 2005

A fully-nonlinear two-dimensional dynamically interfaced nested tidal model has been developed with improved efficiency, usability, relocatability and also adopting different time steps for economizing computational times, which is based on two-dimensional tidal model of Choi(1990) with resolution of $1/15^{\circ}$ inlatitude by $1/12^{\circ}$ in longitude covering the whole Yellow and East China Seas continental shelf. To illustrate the validity and applicability of the present model, numerical model experiment was carried out for tidal distribution in the Yellow Sea and the East China Sea emphasizing the Saemangeum area with enhanced grid system. The results from comparison with observed value showed that the present model gives reasonable agreement. The present modeling system is a relocatable tide forecasting system designed to predict tides at any location within the Yellow Sea and the East China Sea continental shelf sea.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.2
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• pp.239-261
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• 1998

This thesis is concerned with international fisheries cooperation among Korea, China and Japan in the Yellow sea and the East China sea. For this purpose, considerated international fisheries problems relation with these countries refer to literature. Specially adjusted the focus founding of necessity and methods about international fisheries cooperation among these countries. The conclusion is as followed; At first, these countries necessity required international fisheries cooperation because of following reasons. 1. These countries have legal duties for conservation and utilization of marine living resources according to united nations convention law of the sea. 2. These countries that jointly owned semi-closed sea have legal duties for cooperation in respect of fisheries and environment problems. 3. These countries belongs to a same ecosystem and shared with staddling stocks in the Yellow sea and the East china sea. The Second, these countries certainly required international fisheries cooperation following methods. 1. These countries must establish marine area for joint control of marine living resources. 2. These countries must establish tentatively named "International fisheries cooperation body" for deal with comprehensive problems about fisheries.