• Ocean and Polar Research
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• 제30권1호
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• pp.21-31
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• 2008

Analyzing the results of East Sea Regional Ocean Model using a 3-dimensional variational data assimilation scheme, we investigated spatial and temporal variability of the North Korean Cold Current (NKCC) in the East Sea. The climatological monthly mean transport of the NKCC clearly shows seasonal variation of the NKCC within the range of about 0.35 Sv ($=0^6m^3/s$), which increases from its minimum (about 0.45 Sv) through December-January to March, decreases during March and May, and then increases again to the maximum (about 0.8 Sv) in August-September. The volume transport of the NKCC shows interannual variation of the NKCC with the range of about 1.0 Sv that is larger than seasonal variation. The southward current of the NKCC appears often not only in summer but in winter as well. The width of the NKCC is about 35 km near the Korean coast and its core is located under the East Korea Warm Current. The North Korean Cold Water (NKCW), characterized by low salinity and low temperature, is located both under the Tsushima Warm Water and in the western side of the maximum southward current of the NKCC that means the NKCC advects the NKCW southward along the Korean coast. It is revealed that the intermediate low salinity water, formed off the Vladivostok in winter, flows southward to the south of $37^{\circ}N$ through $2{\sim}3$ paths; one path along the Korean coast, another one along $132^{\circ}E$, and the middle path along $130^{\circ}E$. The path of the intermediate low salinity varies with years. The reanalysis fields suggest that the NKCW is advected through the paths along the Korean coast and along $130^{\circ}E$.

• 한국해안해양공학회지
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• 제5권4호
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• pp.414-426
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• 1993

황해 및 동중국해륙붕에서 해류관측에 이용되는 현대적인 방법들을 기술하였고 이 해역 해류의 변화도를 해류관측방법과 관연하여 토의하였다. 이 육붕해역의 보고된 해류관측의 총체적인 자료수집을 수행하였다.

• Fisheries and Aquatic Sciences
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• 제3권2호
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• pp.163-171
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• 2000

A series of numerical experiments are performed to examine the generation of inter-annual variations by an inertial current in an idealized semi-enclosed basin with dimension comparable to that of the East Sea. Model results indicate that the inter-annual variations dominate the kinetic energy spectrum with a peak around the time scales of 2-3 years. These variations are mostly due to the westward propagating meanders and large eddies induced by the instability of current, indicating their dependency on the eddy-resolving capacity of the model. They are generated in the interior of the basin but their energy is largely confined near the western boundary such that the east-west dimension of the basin cannot be considered as a critical factor as long as the basin covers enough western boundary region. Overall, this study suggests that the inter-annual variation observed in the East Sea is due to the meandering and large eddies induced by the instability of the current.

• 한국표면공학회지
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• 제12권1호
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• pp.3-10
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• 1979

Many excellent Al-Zn-In anode have been developed up to the present. But for the purpose of the better performance of Al-Zn-In anodes in sea water the effect of calcium silicon addition on anodic polarization and current capacity of Al-Zn-In anodes was measured and analysed in sea water and artificial sea water. The results and conclusions obtained are summarized as follows. 1) Being compared with Al-Zn-In anodes, Al-Zn-In anodes containing 0.05% calcium silicon had superior characteristics in both anodic polarization and current capacity. 2) Corrosion patterns of the anodes containing calcium silicon were much more uniform than those of Al-Zn-In anodes. 3) In this experiment the most useful anode was Al-4% Zn-0.03% In-0.05% (Ca-Si). It had a capacity of 2.60Amp-hr of current/g and a voltage of 1.13(SCE reference) at anodic current density 1,000 4{\mu}A/cm^2$.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.474-481
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• 2019

The speed trial of a ship is one of the important elements guaranteeing its performance under the contract between the ship owner and shipbuilding company. A speed trial at sea, where the tidal current and waves are suppressed to the maximum, can prevent measurement errors due to external force conditions. On the other hand, it is difficult to maintain a calm sea state in most sea areas determined by the influence of the tidal current, wave, wind, etc. Therefore, this study evaluated a method of simulating a tidal current, which is one of the external force conditions, at the speed test operation of a ship, and applied the simulation result to the plan of a speed trial.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.192-192
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• 2017

• 한국해양학회지:바다
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• 제18권4호
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• pp.163-177
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• 2013

동해 남서부에 위치한 강릉-울릉도간 해역에서 정기여객선 씨스타호에 수온, 염분 및 클로로필a 형광센서를 설치하고 2012년 7월부터 2013년9월까지 북한한류와 동한난류역을 가로질러 매일 왕복조사를 수행하여 해수물성을 연속관측 하였다. 본 연구에서는 염분과 클로로필a 형광 기록과 동해정선관측 및 환경측정망조사 결과, AVISO의 일별 표면해류도 그리고 GOCI 클로로필a 영상을 이용하여 표층해역의 염분 시계열 변동을 분석하였다. 본 연구 결과, 6월부터 10월까지 강릉-울릉도간 표층 해역에 염분범위 33.15~34.12의 고염분수역이 주로 환류의 중간해역이나 강한 북향류의 서쪽 경계역에서 나타났다. 이 수역의 서쪽에는 최저 염분범위가 30.58~33.20로 남향류를 수반하였고 동쪽은 31.30~33.24로 북향류가 수반되었다. 서쪽의 저염분수는 남하하는 북한한류수의 표층수이며, 동쪽의 저염분수는 북상하는 대마난류 표층수이다. 본 연구에서 확인된 북한한류수의 최저염분은 30.36이었으며, 서쪽 저염분수의 동쪽 한계는 강릉 동쪽 약 110 km지점까지, 남쪽으로는 죽변 연안까지 수심 약 5~10 m 이천에서 33.00이하로 분포하였다. 이 저염분수는 하계에 양자강희석수의 혼합으로 저염화된 대마난류 표층수가 북상하면서 수송하는 담수의 규모에 비하여 무시할 수 없을 정도이다. 이것을 본 연구에서는 북한한류수 기원 하계 표층수라고 명명하고자 한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.290-294
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• 2001

Satellite data, with Sea Surface Temperature(SST) by NOAA and Sea Level(SL) by Topex/poseidon, are used to estimate characteristics on the variations and correlations of SST and SL in the East Asian Seas from January 1993 through May 1998. In the oceanic climate, the variations of SL shown the high values in the main current of Kuroshio and the variations of SST shown not the remarkable seasonal variations because of the continuos compensation of warm current by Kuroshio. In the continental climate, SL shown high variations in the estuaries(the Yellow River, the Yangtze River) with the mixing the fresh water in the mouth of estuaries of the saline water in the coasts of continent and SST shown highly the seasonal variations due to the climatic effect of continents. In the steric variations in summer, the eastern sea of Japan, the East China Sea and the western sea of Korea shown the increment of sea level with 10~20cm. But the Bohai bay in China shown relatively the high values of 20~30cm due to the continental climate. Generally the trends of SST and SL increased during all periods. That is say, the slopes of SST and SL presented 0.29$^{\circ}C$/year and 0.84cm/year, respectively. The annual and semi-annual amplitudes shown a remarkable variations in the western sea of Korea and the eastern sea of Japan.

• Journal of Plant Biology
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• 제1권1호
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• pp.11-20
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• 1958

I. Assumption: Mo-kam-ju, Koelreuteria paniculata is a woody plant mainly cistributed over Northern China. Its sporadic growth along the beaches of Korea and Japan is assumed to have been sowed by the seeds transported adrift on the current across the ocean. II. Use and Growth of the Plant: In China, this plant has been cultivated from early times mainly at temples, it seeds being used as rosaries, its flowers for yellow dyes and medicine for the eyes, and its leaves for black dyes. In Korea and Japan, these plants have been cultivated at temples and used as the material for rosaries. No natural growth of these plants was reported until 1919. III. Discoveries: In this domestic area, Dr. Chung Tae Hyun discovered the plant on the beach between Cho-Do and Chang-san-kot, Hwang-Hae Prov. in 1920. The reporter discovered them on the beach at Buk-Ni, Duk-jok-Do in 1948, at An-Hung in 1956 and on the beach at An-min-Do in 1957. In the Japan area, it was discovered for the first time twenty years ago, mainly along the coast line of the Japan Sea and some along the eastern coast line, at Subo, Yamaguchi Prefecture facing the Pacific Ocean. IV. Study and Experiment: A. Seed The seed coat is thick, non-permeable and floatable. A number of seeds were immersed in artificial sea water and fresh water separately. The seeds remained there for a hundred and forty-five (145) days from April 6, 1957 to August 29, 57. Thirty one seeds out of the fifty immersed in salt water and twenty seeds out of the fifty immersed in fresh water remained on the surface of the water, proving them to be non-permeable to both sea and fresh water. Of course, these had retained their germinating capabilities. Five (5) seeds out of twenty from the fresh water and six (6) out of thirty-one from the sea water were successfully germinated after a hole had been drilled in the seed coat and they had been planted. Thus their floating capability, non-permeability and germinating capability after a possible 145 day trip on the flowing currents has been proved satisfactory according to the assumption made above. B. Current As shown in the Data 2 and 3, the sea current initiated in the Pohai Sea flows westward down along the coast line of Korea reaching the southern part during the autumn and winter seasons. This fact also is in favor of the reporter's assumption. V. Discussion and Conclusion: The reporter concludes that, as discussed above, Koelreuteria paniculata which originates in Northern China is transported adrift on the flowing sea current to our western coast line, and also the coast lines of Shantung and Kuangtung of China and it is germinated on the sandy beaches forming new plants. Thus, the seeds drifted down on the southern beach of Korea and have been transported to the Japanese coast, adrift on the Tae-Ma current. Upon fruition, the seeds of the plants which settle on the coasts of western Korea and Japan will migrate to new places. It can be, however, assumed that while the thickness and nonpermeability of the coat enables the long travel in the water, this also can compose a difficulty in germination, consequently in developing a new distribution of this species.

• 풍력에너지저널
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• 제15권1호
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• pp.21-29
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• 2024

In order to respond to environmental changes and various events in the nearby sea area due to the operation of an offshore wind substantiation farm in the Southwest Sea, X-band radar has been installed and operated on a fixed platform since 2018. The X-band radar's monitoring system produces wave and current data through Rutter's Ocean WaveS wave and current (Sigma S6 WaMoS II). In this study, to verify the reliability of the produced data, the accuracy of current and wave data was evaluated by analyzing the correlation with the results obtained by an acoustic doppler current profiler (ADCP). The selected analysis period was a total of 30 days from November 29 to December 28, 2021, the period during which the ADCP survey was conducted. As a result of comparative verification, the current, wave height and peak wave period (H_s > 0.69 m) data observed from the X-band radar showed a high correlation with the results investigated from ADCP. In the future, current and wave data produced by X-band radar are expected to be used as basic data to analyze environmental changes in sea areas and provide information on various events.