• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.19-36
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• 2013

Physiochemical characters of sea waters during summer flood- and winter dry-seasons and their spatial variations were investigated along the coastal area off the eastern South Sea, Korea. Using the hierarchical clustering method, in this study, we present comprehensive analyses of coastal waters masses and their seasonal variations. The results revealed that the coastal water of the study area was classified into six water masses (A to F). During summer season, the surface water was mainly occupied by the coastal pseudo-estuarine water (water mass B) with low salinity and high nutrients and the river-dominated coastal water (water mass C) with low nutrients, respectively. The bottom water was dominated by cold water (water mass D) with very low temperature, high salinity and high nutrients, compared to masses of surface water. Notably, the water mass B, with high concentrations of nutrients (silicate and nitrogen) and low salinity, which is strongly controlled by the water quality of river freshwater, seems to play an important role in controlling the water quality and further regulating physical processes on ecosystem in the eastern coastal area of South Sea. The water mass D (bottom cold water) coupled with a strong thermocline, which exists in near-bottom layer along the western margin of Korea Strait, has a low temperature, pH and DO, but abundant nutrients. This water mass disappears in winter owing to strong vertical mixing, and subsequently may act as a pool for nutrients during winter dry-season. On the other hand, vertically well-mixed water column during the winter season was typically occupied by the Tsushima (water mass E) and the coastal water (water mass F) with a development of coastal front formed in a transition zone between them. These winter water masses were characterized by low nutrient concentration and balance in N/P ratio, compared with summer season with high nutrient concentrations and strong N-limitation. Accordingly, the analysis of water masses will help one to better chemical and biological processes in coastal area. In most of the study area, characteristically, the growth of phytoplankton community is limited by nitrogen, which is clearly different with coastal environment of West Sea of Korea, with a relative lack of phosphorus. It showed the western and the southern coasts in Korea are substantially different from each other in environmental and ecological characteristics.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.2
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• pp.136-140
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• 2011

Monitoring of water surfaces through permanent measurement of hydrodynamic and meteorological data is one of the main requirements in safe and sustainable water management. The Caspian Sea, the major surface water body in Iran, significantly affects more than 600 km of urban and industrial coastline. In the present work, an integrated marine monitoring network for the entire southern coastline of the Caspian Sea was developed. The main design concerns centered on the network measuring components and data recording, checking, filtering, gap recognition, and transferring systems. Four coastal monitoring stations were assigned, along with two regional collecting stations and one central data station for gathering, checking and delivering recorded data at different access levels. Applicable guidelines on selection of measuring devices for both shallow and deep water zones are presented herein.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.343-349
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• 2016

Many minerals and nutrient salts are abundant in Jeju lava sea water. The objective of this study was to evaluate the skin hydration effects of Jeju lava sea water. The skin barrier serves as a protective barrier that prevents the loss of moisture. The water holding capacity and water transport of the epidermis have been proposed to be important determinants of skin hydration. Jeju lava sea water increased the mRNA expression of filaggrin and caspase-14 which is related to natural moisturizing factor (NMF) formation. Aquaporins 3 (AQP3) are proteins that facilitate the transport of water across cell membranes. Jeju lava sea water increased the mRNA expression and protein expression of AQP3. We employed a skin equivalent model to assess the efficacy of Jeju lava sea water. In a skin equivalent model, Jeju lava sea water increased the CD44 (hyaluronic acid receptor) which is related to skin hydration. From these results, we found out Jeju lava sea water maybe help to skin hydration.

• Journal of the Korean Institute of Navigation
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• v.14 no.2
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• pp.61-76
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• 1990

It was found that three different water masses were vertically situated in the western channel of the Korea Strait in summer. Of these water masses , the origin and inflow path of the middle water were discussed and estimated by comparing with water characteristics of neighbouring sea. As a result, (1) the middle water is formed on the continental shelf in the East China Sea by the mixing of the Kuroshio Water and Chinese Continental Coastal Water, (2) the middle water seems intruded through the sea around 127 E west off Kyushu Island and east off Cheju the Island.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.371-378
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• 2021

In this study, in order to analyze the spatial distribution of cold water occurred in the Southeast Sea of Korea, the K-means clustering method was used to analyze the ocean observatory buoy of Gori and Yangpo and GHTSST Level 4 from 2016 to 2018. The buoy data was used to identify the change in sea water temperature and the cold water occurrence at Gori and Yangpo in the Southeast Sea. As a result, the sea water temperature of Gori and Yangpo decreased equally at the cold water occurrence. Therefore, the reciprocal of the sea water temperature and the variance of SST were compared to see the changes of SST when the cold water occurs. When the reciprocal of the sea water temperature increases, the dispersion of SST also increases. Through this, it can be seen that there is a change in the water temperature distribution of SST in the sea when the cold water occurs. After that, K-means clustering was used to classify the cold water. After analyzing the optimal K value for clustering by using the Elbow method, it was possible to classify a region with cold water. Through this, it is estimated that the spatial distribution and diffusion range of the cold water, and it can be estimated and used in future studies to identify damage caused by the cold water and predict spatial spread.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.612-621
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• 2011

The influences of inland pollution sources because of rainfall events on the bacteriological water quality in Geoje Bay, a major shellfish production area in Korea, were investigated. The sanitary status of sea water and shellfish after rainfall events was also evaluated. The flow rates of 13 streams around Geoje Bay showed 6 to 7-fold increases after 15 to 21 mm of rainfall. Peak pollution was observed in the Naegan Stream, the Gandeok Stream and the Seojeong Stream. The calculated impact area of inland pollution sources was 3.1 $km^2$ immediately after 15 mm of rainfall and expanded to 3.5 $km^2$ after 24 hours. These calculations of impacted area matched results from fecal coliform analyses with sea water. The distance between the major pollution source in the bay (the Gandeok Stream) and the station with the worst bacteriological water quality immediately after 15 mm of rainfall, which was below the Korean standard, was 0.8 km in a straight line; this distance increased to 2.0 km after a period of 24 hours. The area impacted by inland pollution sources after a 15 mm rainfall event was wider than after a 21 mm rainfall. Although the flow rate from inland pollution sources was higher, the concentration of fecal coliform in the discharged water was lower after higher rainfall events. These observations corresponded with the results of fecal coliform analyses with sea water samples. According to the evaluation of the influences of inland pollution sources and fecal coliform analyses on sea water and shellfish samples in Geoje Bay, pollutants from inland sources did not reach the boundary line of the shellfish growing area after rainfall events of 15 or 22 mm. The bacteriological water quality of the shellfish growing area in Geoje Bay met the Korean standard and US NSSP requirements for approved shellfish growing areas.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.11-22
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• 2013

SEAWAT, a linked modeling program of Visual MODFLOW was used to analyze the change in groundwater levels and salinity related groundwater dam construction in Cheongsan island, Wando-Gun, Jeollanam-Do. The steady-state model results show the groundwater flow and salinity distribution of the studied area. The groundwater flows from north-west and south-east highlands into the river, located in the middle part of the basin, and is eventually discharged to the ocean. Part of the sea water infiltrates into the river; and through the estuary's alluvium aquifer, the sea water intrusion takes place spreading to about 830 m from the ocean. The transient model results show that after the groundwater dam construction, groundwater levels will rise to a maximum of 2.0 m upstream, and the groundwater storage will increase 21,000 after 10 years. Meanwhile 31% of the total area affected by sea water intrusion will decrease. To conclude, the groundwater dam is a very useful method for a secure water resource in preparation for drought and water shortages in the island regions.

• 한국해양학회지
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• v.20 no.1
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• pp.12-21
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• 1985

In this paper, the most important oceangraphic phenomena of the summer season in the East China Sea are reviewed. The hydrographic conditions in the suface layer above the seasonal thermocline are under great influence from solar heating, fresh water runoff mainly from the Yangtze River, and summer wind fields. In the lower layer below the thermocline, several distinct water masses e.g. the Kuroshio surface water, the Western North Pacific Central Water and the Yellow Sea Bottom Cold Water are intruded in response to the adjustment of the field of mass to the various dynamical processes. The frontal mixing between the intruded Yellow Sea Bottom Cold. Water and the Western North Pacific Central Water takes place in the bottom layer over the continental shelf south off Cheju Is. This mixed water probably has mush influence on the water properties of the intermediate and bottom layer around Cheju Is. and the south coast of Korea.

• Journal of Environmental Science International
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• v.14 no.10
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• pp.945-953
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• 2005

Daily time series of longshore sea surface temperature (SST) data at 3 stations, sea surface SST data at 58 stations in the eastern coast of the Korean Peninsular from 2001 to 2005 were used in order to study the temporal and spatial variations of the upwelling coastal cold water occurred in summer season. When the cold water occurred, SST has been decreased more than $-5^{\circ}C$ in a day. The cold water occurred frequently in the eastern coastal areas of Korea such as Ulgi, Kampo, Jukbyun. Daily variations of cold water temperature were quantified using remote control buoy system at Kijang in the southeastern coastal water from July to August in 2004. Hourly variations of SST occurred around $\pm3^{\circ}C$ when cold water disappeared at Kijang. There were close relationship between the strength of East Korean Warm Current, North Korean Cold Water and the scale of spatio-temporal cold water variations in summer season.

• Journal of the korean society of oceanography
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• v.34 no.3
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• pp.151-166
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• 1999

Both benthic and planktonic foraminifera from Core 97-02 obtained in the northern East China Sea are quantitatively analyzed for reconstructing the paleocenography of late Quaternary. Since the earliest time of the core sediment (last not older than 18000 yr B.P.), the paleo-water depth has changed from less than 20 m to near 100 m at present, which is reflected by the benthic foraminiferal assemblages: before 14000 yr B.P., the water depth was shallower than 20 m; from 14000 to 7500 yr B.P., water depth was 20-50 m; and after 7500 yr B.P., water depth was 50-100 m. The foraminiferal fauna also disclose the water mass history: during the last glacial maximum, the water that dominated the study area might be the coastal water; at the end of the last glacial maximum(14000-9500 yr B.P.), the Yellow Sea Cold Water mostly affected this area; then it gave way to the Yellow Sea Warm Current after 9500 yr B.P.; and finally, the warm water has dominated this area since 9500 yr B.P. because of the westward shift and enhancement of the Kuroshio Current.