• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2818-2826
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• 2010

To study the spatial and temporal variations of sea surface temperature(SST) in the Northeast Asia sea during the period of 1985 to 2009. At first, the buoy data from Korea Meteorological Administration(KMA) and the satellite data have been matched up eight points. The root mean square error and the bias were increased towards the coastal shallow region. The study area which is divided 7 regions from Japan Meteorological Agency(JMA). We analyzed NOAA/AVHRR data by harmonic analysis which is comparison and analysis the center of the each regions. The mean SST varied between $8^{\circ}C$ to $26.0^{\circ}C$. The annual amplitude varied between $7^{\circ}C$ to $24^{\circ}C$. And the annual phase varied between end of July to end of August. Cross-correlation coefficients of mean SST, annual amplitude, and annual phase varied 0.57 to 0.85, -0.04 to 0.81 and 0.35 to 0.80 at all study area, respectively.

• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.16-24
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• 2023

The salinity of sea water is known as a less influencing variable in the calculation of the sound speed of the sea water. This study investigated how the low salinity of sea water affects the vertical structure of the sound speed near the mouth of the Yangtze (Changjiang) River when the diluted fresh water extends toward the East China Sea in the summer. As a result of comparing two types of sound speeds considered measured and fixed salinity, sound speeds appeared distinguishable when the halocline formed steeper than the thermocline due to Yangtze-River Diluted Water (YRDW). In addition, unlikely with fixed salinity conditions, when measured salinity was considered, an underwater sound channel appeared in the middle of the thermocline of which the source depth is located. Accordingly, considering the salinity, this study suggests using Expendable Conductivity Temperature Depth (XCTD) and Expendable Sound Velocimeter (XSV) rather than Expandable Bathy Thermograph (XBT) when calculating sound speed because of the strong halocline due to YRDW in the summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.390-399
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• 2007

In order to investigate the mixing of sea waters on the continental shelf in the northern East China Sea, Korea Ocean Research and Development Institute conducted hydrographic surveys including turbulence measurements using the R/V Eardo in August 2005 and August 2006. The turbulent kinetic energy dissipation rates based on velocity shear measurements are estimated to be $10^{-7}{\sim}10^{4}$, $10^{-7}{\sim}10^{-6}$, and $10^{-7}$ W/kg in the surface layer, bottom layer, and lower thermocline, respectively. The data sets suggest that surface layer water is being constantly mixed by winds. High dissipation rate in the lower thermocline seems to be caused by internal waves. The bottom layer with high dissipation rate also shows high turbidity, indicating the effect of tidal stirring turbulence. The vertical eddy diffusivities are $10^{-3}{\sim}10^{-2}m^2/s$ near the bottom, and these high values appear to arise from both the low stability and high turbulent mixing.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.13-19
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• 2024

An analysis of the coastal water temperature in the Tongyeong waters, the eastern sea of the South Sea of Korea, revealed that the water temperature rose sharply before the typhoon made landfall. The water temperature rise occurred throughout the entire water column. An analysis of the sea surface temperature data observed by NOAA(National Oceanic and Atmospheric Administration) satellites, indicated that sea water with a temperature of 30℃ existed in the eastern waters of the eastern South Sea of Korea before the typhoon landed. The southeastern sea of Korea is an area where ocean currents prevail from west to east owing to the Tsushima Warm Current. However, an analysis of the satellite data showed that seawater at 30℃ moved from east to west, indicating that it was affected by the Ekman transport caused by the typhoon before landing. In addition, because the eastern waters of the South Sea are not as deep as those of the East Sea, the water temperature of the entire water layer may remain constant owing to vertical mixing caused by the wind. Because the rise in water temperature in each water layer occurred on the same day, the rise in the bottom water temperature can be considered as owing to vertical mixing. Indeed, the southeastern sea of Korea is a sea area where the water temperature can rise rapidly depending on the direction of approach of the typhoon and the location of high temperature formation.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.269-272
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• 2006

유기물 증가에 미치는 환경인자를 중심으로 그 수평분포 특성, 원인, 주요오염원의 영향권에 대하여 검토하기 위해 표층 해수와 표층 퇴적물을 조사하였으며, 그 결과를 요약하면 다음과 같다. 유기물변동에 영향을 미치는 인자에 대한 주요 오염원은 크게 섬진강과 동천 등의 담수, 광양시 생활하수, 여수산업단지로 크게 나누어볼 수 있었다. 해수와 퇴적물의 환경인자에 대한 수평분포 특성과 해수의 흐름 등을 고려하여 이들 주요 오염원의 영향권을 구분한 결과, (I) 섬진강 담수의 영향을 많이 받는 해역, (II) 광양시와 동천의 영향이 큰 해역, (III) 여수 산업단지의 영향을 많이 받는 해역으로 나누어졌다. 그리고, 오염원의 영향권별 수질환경인자의 특성으로는 섬진강 담수의 영향을 많이 받는 해역은 낮은 염분, 높은 농도의 $NO_3$-N과 $SiO_2$-Si, 담수와 생활하수의 영향이 큰 해역은 낮은 염분, 높은 농도의 $NO_3$-N, $NH_4$-N, $SiO_2$-Si, 여수 산업단지의 영향을 많이 받는 해역은 표층해수의 경우 높은 수온, 높은 농도의 $NH_4$-N과 $PO_4$-P, 퇴적물의 경우 높은 농도의 $NH_4$-N, $PO_4$-P, $SiO_2$-Si로 특징지울 수 있을 것으로 보인다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.6
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• pp.385-390
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• 1990

To establish an appropriate measure for the prevention of food poisoning from raw fish flesh (sashimi), distribution and population density of Vibrio vulnificus were investigated as environmental factors were changed. The bacteria were detected only in August during the study period from February to November, 1989. The number of bacteria was $2.0\~6.0/100ml$. In August, salinity and pH were low, but water temperature and COD were high as compared to the rest of months.

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

• 한국해양학회지
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• v.25 no.1
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• pp.1-7
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• 1990

Seawater temperature, salinity, inorganic nutrients and the standing crop of phytoplankton species of the 841 water samples from the upper 125 m at 15-40 stations on the 6 semiannual cruises in the southwestern waters of the East Sea (Korea) were studied during the period from September, 1981 to October, 1984, Among the 235 taxa identified two pennate diatioms, cylindrotheca closterium and Nitzschia delicatissima, were the most common and dominant species. The multiple regression analyses between net phytoplankton abundance (dependent variable) and associated environmental factors(independent variables) were applied to the samples from the surface mixed-layer. In spring the coefficients for the seawater temperature was 1. to 4.2 times greater than those for salinity, while the coefficients for the salinity was 2.1 to 3.4 times greater than those for seawater temperature in autumn. Distribution seawater temperature in spring, and salinity in autumn. Schematically the zone of high standing crops moved about on the T-S diagram in a cyclic manner. The distribution of phytoplankton standing crop was quite closely associated with the hydrographic conditions among various kinds of environmental factors studied.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.101-108
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• 2002

The studies using satellite data have been progressed in many area. Especially, Landsat data have been widely used due to its wide coverage. To establish a plan for preserving fishing and environment preservation, measurement of sea temperature is important. The measurement of the sea temperature was made on the ship. However, the measurement on the ship could not provide sufficient information due to the poor timing with relatively longer measurement, and point-based data acquisition. Thus remote sensing technique is required because satellite image data offer more wide coverage in sea temperature monitoring. The purpose of this paper was to study on the sea temperature monitoring with thermal band information of Landsat ETM+. From this study, sea temperature map of Cheju island has been made efficiently.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.335-335
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• 2015

행주대교 하류 약 3km 지점에 위치한 신곡수중보는 한강종합개발 사업 중 하도정비로 인한 상시수위 저하로 인해 발생하는 문제를 해결하기 위해 설치되었으며, 취수장의 취수심 확보, 주운수심 확보, 염수 역류에 의한 생태계의 변화 방지, 하천 주면의 지하수위 저하 방지 목적으로 건설되었다. 본 연구에서는 신곡수중보의 존치, 이전 혹은 철거로 인한 수질변화를 모의를 실시하였다. 한강 본류와 임진강 합류를 고려하여 총 495개 수질모의 셀을 구성하였고, 수질모의를 위한 WQ Cell은 길이가 100 m~340 m로 임진강 47개, 한강 448개로 총 495개의 셀로 구성하였으며, 주요 지천이나 오염원으로 신곡보 하류에는 공릉천, 신곡보와 잠실보 사이에는 창릉천, 서남과 난지물 재생센터, 안양천, 홍제천, 중랑천, 탄천, 잠실보 상류에는 왕숙천, 월문천, 덕풍천 등 9개 지천과 2개 물 재생센터를 포함하였으며 잠실보 상류에서의 생활용수 취수를 고려하였다. 수온, BOD, 조류의 경계조건은 환경부에서 제공한 2011년 3월과 4월의 측정자료를 사용하였다. 그 결과, 신곡보 철거시 수온의 변화는 서해로부터의 차가운 해수의 역류 증가로 임진강, 파주, 전류, 장항습지까지 수온이 최대 $0.94^{\circ}C$ 크게 하강할 것으로 나타났으나 행주, 가양, 영등포는 오히려 수온이 $0.03{\sim}0.04^{\circ}C$ 미미하게 상승할 것으로 나타났으며 현재의 신곡보가 수온의 급격한 변화를 완층하는 역할을 담당하여 왔으나 보가 철거되면서 이러한 수온 완충역할이 사라지기 때문으로 분석되었다. 신곡보 철거시 BOD 농도의 변화는 잠실보 하류쪽으로는 BOD 농도가 최대 1.02 mg/l 감소하는 등 전반적으로 수질이 크게 개선될 것으로 나타나는 반면 잠실보 상류쪽으로는 BOD 농도가 최대 0.56 mg/l 증가하며 현재의 1급수 수질에서 2급수로 수질이 악화되어 상수원 수질 관리가 어려울 것으로 예상되었다. 신곡보 철거시 조류 농도의 변화는 잠실보 하류쪽으로 조류 농도가 최대 1.85 mg-A/l 감소하는 등 전반적으로 수질이 크게 개선될 것으로 나타나는 반면 잠실보 상류쪽으로는 조류 농도가 최대 0.40 mg-A/l 증가하며 고조위 기간에는 조류주의보 기준 1.5 mg-A/l를 초과하는 경우도 발생하여 상수원 취수에 문제가 발생할 가능성이 있는 것으로 나타났다.