• Journal of Environmental Science International
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• v.17 no.2
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• pp.141-148
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• 2008

In order to investigate the effect of inflow of Yangze river on the distribution of chlorophyll-${\alpha}$, the results of serial oceanographic observation during 2000-2005 were used. The oceanographic conditions in the northern East China Sea is influenced by the Tsushima Warm Current and low saline water derived from the Yangze river. The distributions of these water masses vary significantly by the season in the northern East China Sea. The sea surface temperature and salinity were stable and concentrations of chlorophyll-${\alpha}$ were low in the eastern part of $126^{\circ}E$. On the contrary, the salinity was significantly influenced by the low saline water derived from Yangze river with the high concentrations of chlorophyll-${\alpha}$. It is suggested that the low saline water inflowed from the Yangze river affects high concentrations of chlorophyll-${\alpha}$ in the northern East China Sea in summer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.1021-1032
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• 1997

Satellite-tracked drifters deployed in the East Sea since 1991 are used to study the Tsushima Current (TC). It is found that the TC is a steady current with a mean speed of 10 cm/s before it enters the East Sea. Only during the summer, the TC flows along Honshu Island with a mean speed of $30\~40\;cm/s$ and then exits through the Tsugaru Strait. In fall and winter, the TC does not follow the coast along Honshu Island but it enters into the interior of the East Sea before it reaches the Tsugaru Strait. The water that passes the West Channel of the Korea Strait mostly comes from the western East China Sea and spreads into the interior of the East Sea. It also forms the large eddies in the southern East Sea. The outflow through the Tsugaru Strait comes from the interior of the East Sea in all seasons except summer. The mean speed of the Tsugaru Strait outflow is about 60 cm/s. The largest current variability is found in the eastern central area of the East Sea, south of sub-polar front.

• Journal of the korean society of oceanography
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• v.39 no.1
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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.

• Journal of the Korean earth science society
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• v.35 no.6
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• pp.439-466
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• 2014

Since the unification of the diverse oceanic current maps of the East Sea in secondary school science textbooks has recently been accomplished, there have been increasing requirements for the production of a current map of the Yellow Sea (YS) and the East China Sea (ECS). This study, as its first attempt, facilitated the prospective production process of the unified oceanic current maps in YS and ECS by analyzing the maps of scientific articles and those of the present textbooks as of 2014. First of all, the analogue current maps of the textbooks and scientific articles were digitalized to retrieve the characteristics of current maps quantitatively and to make intercomparison of the maps. The currents of both YS and ECS such as the Kuroshio Current, the Taiwan Warm Current, the Tsushima Warm Current, the Yellow Sea Warm Current, the Chinese Coastal Current, the Korea Coastal Current, and the Changjiang River Flow were selected and analyzed. We made 18 items to investigate the paths of the currents. Analyses of the oceanic current maps of secondary school science textbooks and scientific articles with respect to the selected criteria revealed that the current maps of the textbooks were considerably different from the up-to-date knowledge of the current maps acquired from the scientific articles. In addition, since the currents of YS and ECS have strong seasonality, we suggest that they should be presented with at least two current maps for summer and winter in the textbooks, which may go through active discussions among experts.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.225-242
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• 2012

This is the first attempt to produce simultaneous surface current field from satellite altimeter data for the entire East Sea and to provide surface current information to users with formal description. It is possible to estimate surface geostrophic current field in near real-time because satellite altimeters and coastal tide gauges supply sea level data for the whole East Sea. Strength and location of the major currents and meso-scale eddies can be identified from the estimated surface geostrophic current field. The mean locations of major surface currents were explicated relative to topographic, ocean-surface and undersea features with schematic representation of surface circulation. In order to demonstrate the practical use of this surface current information, exemplary descriptions of annual, seasonal and monthly mean surface geostrophic current distributions were presented. In order to objectively classify surface circulation patterns in the East Sea, empirical orthogonal function (EOF) analysis was performed on the estimated 16-year (1993-2008) surface current data. The first mode was associated with intensification or weakening of the East Korea Warm Current (EKWC) flowing northward along the east coast of Korea and of the anti-cyclonic circulation southwest of Yamato Basin. The second mode was associated with meandering paths of the EKWC in the southern East Sea with wavelength of 300 km. The first and second modes had inter-annual variations. The East Sea surface circulation was classified as inertial boundary current pattern, Tsushima Warm Current pattern, meandering pattern, and Offshore Branch pattern by the time coefficient of the first two EOF modes.

• 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.

• Ocean and Polar Research
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• v.28 no.2
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• pp.153-161
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• 2006

To investigate inflow path of the East Sea Intermediate Water (ESIW) into the Ulleung Basin, hydrographic data surveyed in July 2005 were analyzed. The ESIW was characterized by the Salinity Minimum Layer (SML) within a depth range of 100 to 360 meters. Averaged potential temperature and salinity of the SML were $1.835^{\circ}C$ and 34.049 psu, respectively. Mean potential density $({\sigma}_{\theta})$ of the SML was 27.221 with a standard deviation of 0.0393. On isopycnal surfaces of 27.14 and 27.18 $({\sigma}_{\theta})$ which correspond to upper layers of the ESIW, the coastal low salinity water was separated from the offshore low salinity water by the relatively warm and saline water which might be affected by the Tsushima Warm Current Water. Relatively cold and fresh water, however, intruded into the Ulleung Basin from the region of Korean coast on isopycnal surfaces of 27.22 and 27.26 which was lower layer of the ESIW. The salinity distribution in the isopycnal layer of $27.14{\sim}27.26$ with acceleration potential on 27.22 up surface also showed clearly that the low salinity water flowed from the coastal area and intruded into the Ulleung Basin. This implies that the ESIW flows ken the north to the south along the east coasts of Korea and spreads into the Ulleung Basin in summer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.61-73
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• 2016

Water mass distribution and currents were investigated off the east coast of Korea near the Hupo Bank using the CTD and ADCP data from June to August 2010. The typical water masses were: (1) Tsushima Surface Water (TSW) from the East Korean Warm Current (EKWC) in the surface layer, (2) a shallow thermocline at 20-30 m depth, (3) Tsushima Middle Water (TMW) of high salinity (>34.2) below the pycnocline, (4) North Korean Cold Water (NKCW) of low salinity (<34.05) and low temperature (<4°C) in the lower layer. In June, a double eddy was observed in which a cold filament intruded cyclonically from the south around a pre-existing cold-core eddy. A burst of strong southward current was recorded in mid-August due to a warm filament from the meandering EKWC. Current in the N-S direction was predominant due to topographic effects, and the direction of the northward EKWC was frequently reversed in its direction due to the eddy-filament activity, whereas the influence of the wind was not noticeable. The vertical structure of the current was of a two-layer system, with the northward EKWC in the upper layer and weak southward flows corresponding to the North Korean Cold Current (NKCC) in the deeper layer.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1994.04a
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• pp.81-81
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• 1994

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.177-184
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• 2003

Numerical simulation on marine wind and sea surface elevation was carried out using both three-dimensional hydrostatic and non-hydrostatic models and a simple oceanic model from 0900 LST, August 13 to 0900 LST, August 15, 1995. As daytime easterly meso-scale sea-breeze from the eastern sea penetrates Kangnung city in the center part as basin and goes up along the slope of Mt. Taegullyang in the west, it confronts synoptic-scale westerly wind blowing over the top of the mountain at the mid of the eastern slope and then the resultant wind produces an upper level westerly return flow toward the East Sea. In a narrow band of weak surface wind within 10km of the coastal sea, wind stress is generally small, less than l${\times}$10E-2 Pa and it reaches 2 ${\times}$ 10E-2 Pa to the 35 km. Positive wind stress curl of 15 $\times$ 10E-5Pa $m^{-1}$ still exists in the same band and corresponds to the ascent of 70 em from the sea level. This is due to the generation of northerly wind driven current with a speed of 11 m $S^{-1}$ along the coast under the influence of south-easterly wind and makes an intrusion of warm waters from the southern sea into the northern coast, such as the East Korea Warm Current. On the other hand, even if nighttime downslope windstorm of 14m/s associated with both mountain wind and land-breeze produces the development of internal gravity waves with a hydraulic jump motion of air near the coastal inland surface, the surface wind in the coastal sea is relatively moderate south-westerly wind, resulting in moderate wind stress. Negative wind stress curl in the coast causes the subsidence of the sea surface of 15 em along the coast and south-westerly coastal surface wind drives alongshore south-easterly wind driven current, opposite to the daytime one. Then, it causes the intrusion of cold waters like the North Korea Cold Current in the northern coastal sea into the narrow band of the southern coastal sea. However, the band of positive wind stress curl at the distance of 30km away from the coast toward further offshore area can also cause the uprising of sea waters and the intrusion of warm waters from the southern sea toward the northern sea (northerly wind driven current), resulting in a counter-clockwise wind driven current. These clockwise and counter-clockwise currents much induce the formation of low clouds containing fog and drizzle in the coastal region.