• Title/Summary/Keyword: High Sea

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Statistical Analysis of NOAA/AVHRR High Resolution Weekly SST in the East Sea: Regional Variability and Relationships with ENSO (동해지역 NOAA/AVHRR 고해상도 주평균 해수면 온도의 통계적 분석 : 지역적 변동성과 엘니뇨/남방진동과의 관계성)

  • Kwon, Tae-Yong;Lee, Bang-Yong;Lee, Jeong-Soon
    • Ocean and Polar Research
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    • v.23 no.4
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    • pp.361-376
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    • 2001
  • The characteristics of SST variability in the East Sea are analyzed using NOAA/AVHRR weekly SST data with about $0.18^{\circ}{\times}0.18^{\circ}$ resolution ($1981{\sim}2000$) and reconstructed historical monthly SST data with $2^{\circ}{\times}2^{\circ}$ resolution $(1950{\sim}1998)$. The distinct feature of wintertime SST is high variability in the western and eastern parts of $38^{\circ}{\sim}40^{\circ}$ latitudinal band, which are the northern boundary of warm current in the East Sea during winter. However, summertime SST exhibits variability with similar magnitude in the entire region of the East Sea. The analysis of remote correlation also shows that SST in the East Sea is closely correlated with that in the region of Kuroshio in winter, but in summer is related with that in the western and eastern regions of the same latitudes. From these results it is postulated that the SST variability in the East Sea may be related with the variations of East Korean Warm Current and Tsushima Warm Current in winter, but in summer probably with the variations of atmospheric components. In the analysis of ENSO related SST anomaly, a significant negative correlation between SST anomalies in the East Sea and SST anomalies in the tropical Pacific is found in the months of August-October (ASO). The SST in the ASO period shows more significant cooling in E1 $Ni\~{n}o$ events than warming in La $Ni\~{n}a$ events. Also, the regional analysis shows by the Student's t-test that the negative SST anomalies in the E1 $Ni\~{n}o$ events are more significant in the southwestern part of the East Sea.

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Relationship between the Distribution of Water Masses and that of Demersal Fishes in the East China Sea in Spring

  • Cho Kyu Dae;Kim Hee Yong
    • 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.

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A Simulation of Directional Irregular Waves at Chagui-Do Sea Area in Jeju Using the Boussinesq Wave Model (Boussinesq 모델을 이용한 제주 차귀도 해역의 다방향 불규칙파 시뮬레이션)

  • Ryu, Hwang-Jin;Shin, Seung-Ho;Hong, Key-Yong;Hong, Seok-Won;Kim, Do-Young
    • Journal of Ocean Engineering and Technology
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    • v.21 no.1 s.74
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    • pp.7-17
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    • 2007
  • Based on the Boussinesq wave model, the wave distribution in the Chagui-Do sea area in Jeju was simulated by applying the directional irregular waves at an incident boundary. The time and spatial variations of monthly mean wave height and period were investigated, which aims to provide basic information on optimal sites for wave power generation. The grid size and time interval of the Boussinesq wave model were validated by examining wave distributions around a surface piercing wall, fixed at sea bottom with a constant slope. Except for the summer season, the significant wave height is dominated by wind waves and appears to be relatively high at the north sea of Chagui-Do, which is open to the ocean, while it is remarkably reduced at the rear sea of Chagui-Do because of its blocking effect on incident waves. In the summer, the significant wave height is higher at the south sea, and it is dominated by the swell waves, which is contributed by the strong south-west wind. The magnitude of significant wave height is the largest in the winter and the lowest in the spring. Annual average of the significant wave height is distinctively high at the west sea close to the Chagui-Do coast, due to a steep variation of water depth and corresponding wave focusing effect. The seasonal and spatial distribution of the wave period around Chagui-Do sea reveals very similar characteristics to the significant wave height. It is suggested that the west sea close to the Chagui-Do coast is the mast promising site for wave power generation.

Changes in Corrosion Rate of Gas Turbine Engines by the Korean Sea Area (우리나라 해역별 가스터빈엔진 부식률의 변화)

  • Oh, Kyungwon;Hur, Jangwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.137-138
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    • 2017
  • The sea of the Korean peninsula has various marine changes, including naval vessels, naval operational aircrafts, air force fighters, coastal airports and airfields. In particular salt directly affected by the marine environment, equipment operating in a high temperature / high speed as the gas turbine is the high temperature corrosion(Hot Corrosion) caused by sulfur components and salinity of the fuel used. When the height of the demister (air intake) is less than 7m, the salinity entering the sea increases and the corrosion increases rapidly. In addition, the weapon systems operating in the East Sea than the West Sea showed a 17% increase in corrosion rate due to the relatively high salinity scattered by saline, wind, and wave. In order to minimize the salinity inflow, it should be operated at more than 13m from the sea to minimize rapid hot corrosion.

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Variation of the Sea Level in the Korean seas Using Altimeter Data (TOPEX/POSEIDON)

  • Seo, Won-Chan;Yoon, Hong-Joo
    • Journal of information and communication convergence engineering
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    • v.6 no.4
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    • pp.430-433
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    • 2008
  • A merged altimeter data products are used to estimate sea level variation in the East Sea between 1993 and 2006. The altimeter data show a high correlation coefficient (0.85) after applying gaussian low pass filter for 180days at Ulleung island. The both of Mukho coast and Ulleung island are minimal sea level in March to May and maximal in September to November. Sea level of Mukho coast is higher than that of Ulleung island during March to May, while Mukho coast is lower during September to November because the North Korea Cold Current flows along the coast line of Mukho. Generally sea level variation at Mukho coast and Ulleung island associated with seasonal variations.

A Study on the Characteristics of the Sea Ship and the River Ship′s Hull Form in the Chosun Period of Korea (조선시대 해선과 강선의 선형특성)

  • Choi, Byung-Moon
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.6
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    • pp.102-113
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    • 2004
  • A name of 'Sea Ship' and 'River Ship' had been used based on the comprehension for the difference of ship's hull form in Chosun period. We can find a number of literature describing the situation which transferred the cargo from Sea Ship to River Ship because Sea Ship could not go upstream in the river of which the current is fast and the water depth is low. The reason why Sea Ship could not go upstream was that the bottom of Sea Ship was narrow, it means the non-flat bottom. Generally Sea Ship had short length, wide breadth, so L/B of 2.2∼3.0, and high draft and depth. River Ship has long length, narrow breadth, so L/B of 5.0∼6.3, and low draft and the flat bottom in order to adapt to the low water depth of the river.

Phamalogical effect and component of sea buckthorn(Hippophae rhamnoides L.) (비타민나무의 약리 효과 및 구성 성분)

  • Kim, Ju-Sung;Yu, Chang-Yeon;Kim, Myong-Jo
    • Journal of Plant Biotechnology
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    • v.37 no.1
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    • pp.47-56
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    • 2010
  • Sea buckthorn (Hippophae rhamnoides L.) is deciduous shrubs in the genus Hippophae, mainly cultivated in Europe and Asia. Sea buckthorn berries have a high vitamin C, vitamin E, carotenoids, carbohydrates, protein, organic acids, dietary minerals, triterpenoids, polyphenolic acids and amino acids. Extracts of sea buckthorn berries have anti- obesity, anti-oxidantive, anti-microbial, anti-ulcerogenic, anti-diabetic and nutritional effects. Sea buckthorn used as a traditional medicine for the treatment of cough, aid digestion, invigorate blood circulation and alleviate pain. Extracts of sea buckthorn branches and leaves was administered to humans and animals to treat gastrointestinal distress in Mongolia. This paper briefly reviews the most relevant experimental data on the pharmacological effects and isolated component of sea buckthorn. And, we also describe the importance of sea buckthorn as the environmental-friendly crops.

The Effect of Building Morphology on Sea Breeze Penetration over the Kanto Plain - Analysis of Mean Kinetic Energy Balance of Moving Control Volume along Sea Breeze -

  • Sato, Taiki;Ooka, Ryozo;Murakami, Shuzo
    • International Journal of High-Rise Buildings
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    • v.1 no.2
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    • pp.73-80
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    • 2012
  • In order to use sea breezes to counter the heat island phenomena, i.e. to promote urban ventilation, it is necessary to clarify the effect of building morphology and height on large-scale wind fields. In this study, the sea breeze in the vicinity of the Kanto Plain in Japan is simulated using a mesoscale meteorological model incorporating an urban canopy model, and the inland penetration of sea breezes is accurately reproduced. Additionally, a mean kinetic energy balance within a domain (Control Volume; CV) moving along the sea breeze is analysed. From the results, it is clarified that the sea breeze is interrupted by the resistance and turbulence caused by buildings at the centre of Tokyo. The interruption effect is increased in accordance with the height of these buildings. On the other hand, adverse pressure gradients interrupt in the internal region.

Rheological Study on bentonite Clay Sedimentation with various concentrations of Sea water (해수의 농도 변화에 따른 bentonite 침전에 대한 유변학적 고찰)

  • 최상원;서호준
    • Journal of Environmental Science International
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    • v.5 no.1
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    • pp.35-41
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    • 1996
  • For studying of coagulation and sedimentation in estuarine clay, we obtained several flow curves with various concentrations of sea water by using Coutte type rotational rheometer. The initial shear stress on high concentration of sea water was observed big, but after this, its value is decreasing with increasing shear rate. The maximum pick of shear stress is decreasing with the decreasing of concentration of sea water The trend is same totally above for viscosity. The sedimentation times with the concentration of sea water vary in $\infty$ ~ 5 minutes. The zeta potential is changed dramatically between 114 and 118 concentration of sea water. That is consistent with the sedimentation graph. From these results, the phenomena of coagulation and sedimentation can be explained with viscoelastic terms on structual formation among particles by the changes of surface potential affected from contacting sea water to dispersed particles.

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Sea level observations in the Korean seas by remote sensing (원격탐사를 이용한 한반도 주변해역의 해면변화 및 표층순환)

  • 윤홍주;김승철;변혜경;황화정
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.339-342
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    • 2003
  • Sea level variations and sea surface circulations inthe Korean seas were observed by Topex/Poseidon altimeter data from 1993 through 1997. In sea level variations, the West and South Sea showed relatively high variations with comparison to the East Sea. Then, the northern and southern area in the West Sea showed the range of 20-30cm and 18-24cm, and the northern west of Jeju island and the southern west of Tsushima island in the South Sea showed the range of 15-20cm and 10-15cm, respectively. High variations in the West Sea was results to the inflow in sea surface of Yellow Sea Warm Current (YSWC) and bottom topography. Sea level variations in the South Sea was due to two branch currents (Jeju Warm Current and East Korea Warm Current) originated from Kuroshio Current (KC). In sea surface circulations, there existed remarkably three eddies circulations in the East Sea that are mainly connected with North Korea Cold Current (NKCC), East Korea Warm Current (EKWC) and Tushima Warm Current (TWC). Their eddies are caused basically to the influence of currents in sea surface circulations; Cyclone (0.03 cm/sec) in the Wonsan bay on shore with NKCC, and anticyclone (0.06 cm/sec) in the southwestern area of Ulleung island with EKWC, and cyclone (0.01 cm/set) in the northeastern area of Tushima island with TWC, respectively.

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