• Journal of Environmental Impact Assessment
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• v.21 no.3
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• pp.461-468
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• 2012

In general, long-term changes of ecological factors take a pulse form in which they interact with other factors and go through a repeated increasing and decreasing cycle. The coupling of the two approaches the grid model and the box model in ecological modeling can lead to an in-depth understanding of the environment. The study analyzes temporal variations of major storages with an energy system model that formulizes effectively the relationships among nutrients, phytoplankton, and zooplankton in the Yellow Sea and the East China Sea. An increase of light intensity and standing stock of nutrient increase the magnitude and frequency of pulsing. Also, an immense reduction of nutrient concentration can cause extinction of the pulsing and bring about a steady state. It is concluded that the nutrient loads in freshwater discharge from the Yangtze affect the cycles of major ecological components as well as water quality variables and play an important role in the marine ecosystem.

• Journal of the Korean earth science society
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• v.44 no.1
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• pp.1-12
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• 2023

Oceanic wind waves have been recognized as one of the important indicators of global warming and climate change. It is necessary to study the spatial and temporal variability of significant wave height (SWH) and wave direction in the Yellow Sea and a part of the East China Sea, which is directly affected by the East Asian monsoon and climate change. In this study, the spatial and temporal variability including seasonal and interannual variability of SWH and wave direction in the Yellow Sea and East China Sea were analyzed using European Center for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5 (ERA5) data. Prior to analyzing the variability of SWH and wave direction using the model reanalysis, the accuracy was verified through comparison with SWH and wave direction measurements from Ieodo Ocean Science Station (I-ORS). The mean SWH ranged from 0.3 to 1.6 m, and was higher in the south than in the north and higher in the center of the Yellow Sea than in the coast. The standard deviation of the SWH also showed a pattern similar to the mean. In the Yellow Sea, SWH and wave direction showed clear seasonal variability. SWH was generally highest in winter and lowest in late spring or early summer. Due to the influence of the monsoon, the wave direction propagated mainly to the south in winter and to the north in summer. The seasonal variability of SWH showed predominant interannual variability with strong variability of annual amplitudes due to the influence of typhoons in summer.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.26-34
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• 2004

The evolution of intricate and striking patterns of suspended sediments (SS), which are created by certain physical dynamics in the East China and Yellow Seas, has been investigated using satellite ocean color imageries and vertical profiles of particle attenuation and backscattering coefficients. The structure of these patterns can reveal a great deal about the process underlying their formation. Sea surface temperature (SST) analyzed from the Advanced Very High Resolution Radiometer (AVHRR) thermal infrared data were used to elucidate the physical factors responsible for the evolution of suspended sediment patterns in the East China Sea. The concomitant patterns of suspended sediments were tracked from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color data. The detailed examination about these patterns gave birth to the definition of the evolution of suspended sediments (SS) into four stages: (1) Youth or Infant stage, (2) Younger stage, (3) Mature stage, and (4) Old stage. We describe about the three directional forces of the tidal currents, ocean warm currents and estuarine circulations that lead to occurrence of various stages of the evolution of suspended sediments that increase turbidity at high levels through out the water column of the inner and outer shelf areas during September to April. The occurrence of these four stages could be repeatedly observed. In contrast, vertical profiles of the particle attenuation ($c_{p}$) and backscattering ($b_{bp}$) coefficients displayed obvious patterns of the propagation of suspended sediment plume from the southwestern coastal sea that leads to eventual collision with the massive sediment plume originating from the Yangtze banks of the East China Sea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.327-339
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• 2003

During the winter in February 1998, January and April 1999, interdisciplinary research was conducted in a large area including the South Sea of Korea and northern East China Sea to examine distribution and structure. Water masses identified from the observed data are Warm Water originated from Tsushima Warm Current, Yellow Sea Cold Water (Northern or Central Cold Water) and Korean Southern Sea Cold Water. In the southern Yellow Sea, Warm Water originated from Tsushima Warm Current, flowing into the Cheju Strait after turning around the western Cheju Island, makes a front of '┍' shape, which is bounded by the Yellow Sea Central Cold Water in the southern part of Daeheuksan Island and by the Yellow Sea Northern Cold Water in the eastern part of the Yangtze Bank. This front changes its corner shape and position with strength of the warm water extension toward northwestern Yellow Sea. The position and structure of the fronts off the southwestern tip of the Korean peninsular and near the Yangtze Bank varies with observation period. In the front in the South Sea of Korea, cold coastal water which if formed independently due to local cooling, ,sinks along the sloping bottom. We explained the processes of variations in the distribution and structure of these winter fronts in terms of up-wind and down-wind flow by the seasonal monsoon, heat budget through the sea surface and density difference across the fronts.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.392-405
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• 2010

The population of small yellow croaker, Larimichthys polyactis, in the Yellow and East China Seas has decreased significantly since the mid 1970s. Several management measures have been introduced to conserve it, but population size remains low. To rebuild this population, it is now necessary to consider more effective management methods based on the stock assessment. To determine long-term population changes, fishery and biological data collected over 34 years (1969-2002) were analysed. Yearly fish length compositions were analysed for the time periods 1968 through 1970, 1978 through 1982, and 1993 through 2002; and catch data was available from 1969 to 2002. Annual population sizes were calculated based on length composition, the relationship between total length and body weight, and total landings. Analyses showed that since the 1970s, average size of harvested fish decreased; the proportion of less mature fish (smaller than the 50% maturity length, 19cm) in catches has increased and the estimated biomass has decreased significantly. Consequently, the main management recommendation is that juvenile fish need to be better protected to allow the rebuilding of resources to a more sustainable population level. This will require fish size limit, permissible mesh size, and closed area and season regulations.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.2
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• pp.137-145
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• 1996

Effects of nonlinear terms on the generation of M$_2$ tide residual elevation and M$_4$ tide in the Yellow Sea and the East China Sea are investigated using a depth-integrated two-dimensional nonlinear M$_2$tidal model. The model domain (117$^{\circ}$E-130$^{\circ}$E, 24$^{\circ}$N-41$^{\circ}$N) covers the whole region of the Yellow Sea and the East China Sea with grid resolution of 1/6$^{\circ}$ in longitude and 1/8$^{\circ}$in latitude. A radiational boundary condition is used along the open boundaries. Calculations show that advection terms yield negative residual elevation, while shallow-water terms in continuity equation yield positive residual elevation. The contribution of both advection terms and shallow-water terms to tile generation of the M$_4$ constituent is more than 90 percents, but that of quadratic bottom friction terms to the M$_4$ constituent is comparatively small.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.2
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• pp.125-132
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• 1984

A simple stratification/mixing model has been developed for shelf waters of the Yellow Sea and the East China Sea. The results are summarized in the form of maps of stratification parameter which utilized the estimates of tidal dissipation from non-linear two-dimensional tidal model of the region. Ultimate aim of this study is to evaluate the applicability of the tidal mixing criteria to the Yellow Sea especially for the offshore region near Taean Peninsula in the west coast of Korea using hydrographic data and computed stratification parameter.

• 한국해양학회지
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• v.20 no.1
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• pp.1-11
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• 1985

Two Typhoon surges generated during the period of July-August 1978 are investigated dynamically using a vertically-integrated finite-difference model of the Yellow Sea and the East China Sea, Computed residuals are compared oeth hourly records from selected tide gauges (Inchon, Kunsan, Mokpo, Jeju, Yeosu) slong the coast of Korea. Some of the preliminary results are presented and discussed. This initial hindcast study has been undertaken in association with SEASAT-A altimeter data correction work in the East China Sea.

• The Journal of Fisheries Business Administration
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• v.39 no.2
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• pp.81-108
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• 2008

Since the declaration made by UN Convention on the Law of the Sea on EEZs, The open seas of Northeast Asia, considerd as a convention area, needed new agreements in conformity with the changes brought by the introduction of the Exclusive Economic Zone(EEZ) system. The Contracting Parties of these agreements set up their own EEZs, which extend certain ranges from their baselines, Fishing in the other party's EEZ is done based on mutual agreements, which take into account traditional fishing activity in the zones. Seperate fishries management systems, in accordance with the relevant legal status of the waters, are applied to individual overlapping areas: Middle Zone in the Bast Sea and the waters south of jeju Island, Interim Measure Zone in the Yellow Sea and East China Sea, and the Transitional Zone in the Yellow Sea. They decided to conclude fisheries agreements as the provisional agreement under Article 74(3) of the UN Convention before the delimitations of the EEZs to avoid the territorial disputes. China and Japan concluded the Fishries Agreement in the November 1997, allowing each coastal State 52 mile EEZ. it was followed by Korea and Japan in September 1998, reaching a final compromise. And also Korea and China came to a satisfactary settlement in November 1998. Fisheries agreements have been established between the three North-east Asian States, the agreement are all bilateral. That implies inefficient resource management on the overlapping waters of the three states, especially on the East China Sea. The Korea-Japan Fisheries Agreement and the China-Japan Fishery Agreement worked as governing rules in the North-east Asian seas before the establishment of EEZs (Exclusive Economic Zones). However the conclusion of the bilateral fishery agreements, Korea China and Japan have developed EEZs, and these three countries have competed for the exploitation of fisheries resources. Therefore, the issue of fisheries resource management was no longer a single countries' problem and emerged as a common issue facing these three countries. In recognition of the above-mentioned problem, it is needed for the construction of cooperative System fishery management in the North-east Asian seas. Therefore, cooperative measures should be establishied. The final goal of the construction of fisheries management cooperative system is to establish sustainable fisheries in the North-east Asian seas. However, there is a big difference in fisheries management tools, fishing gear, exploitation rate of species, etc. This implies that a careful approach should be taken in order to achieve the cooperative fisheries management among Korea, China and Japan. conclusionly, the Governments of Korea, China and Japan should complement three bilateral agreemens, and which they prepares to 'Fisheries Resource Restore Program' Between Korea, China and Japan in the adjacent waters south of Jeju Island.

• Journal of the Korean earth science society
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• v.25 no.1
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• pp.1-9
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• 2004

The clay minerals of thirty-four bottom sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sediment source and the dominant circulation pattern. The predominant clay mineral in our study area is illite comprising more-than 70% of whole clay fraction. The highest concentration of illite (>72%) is found in the southeastern offshore parts beyond the reach of terrigenous input from the Cheju Island. It means that these illites are largely transported by the Kuroshio Current from the South China Sea. Smectite is highly concentrated in the northwest middle part and in the outer-shelf mud patch. It seems to be due to the high supply of smectite transported from China where the fine-grained sediments are discharged from the modern and ancient Huanghe River. The relatively high abundance of kaolinite is likely derived from the Changjiang River via Taiwan ·Warm Current. In contrast, the large amounts of chlorite and high chlorite/kaolinite ratios occur in the northwestern are, reflecting the transportation by the Huanghai Sea Coastal Current from the southern Yellow Sea.