• 한국환경과학회지
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• 제12권9호
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• pp.943-948
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• 2003

Variation of the polar front in the East Sea is studied using temperature and dissolved oxygen data obtained from Japan Meteorological Agency from 1972 to 1999. Variation of the polar front in the East Sea has a close relation to the variation of the Tsushima Warm Current (TWC). When the TWC spreads widely in the East Sea, polar front moves northward. The spatial variation of the polar front is greater in the southwestern area of the East Sea and the northern area of Tsugaru Strait where the variation of the TWC's distribution area is greater than those in others of the East Sea. Hence, in the southeastern area of the East Sea, that is, between near Noto peninsula and Tsugaru Strait, the spatial variation of the polar front is not so wide as in the southwestern area because the flow of TWC is stable.

• 한국수산과학회지
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• 제30권6호
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• pp.1033-1043
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• 1997

In order to understand the generation mechanism of the Ulleung Eddy, we carried out a series of numerical experiments using the nonlinear 11/2 - layer model allowing the inflow of the Tsushima Current. According to our numerical results, the Ulleung Eddy was generated due to the inflow variations of the Tsushima Current. Its inflow through the Korea Strait was deflected to the east due to the Coriolis force and the nonlinear self advection. Thus, an anticyclonic motion was formed at the north of the Korea Strait. The inflow became a coastal boundary current, and finally flowed out model ocean through the eastern exit. When the speed of inflow decreased slowly, the eddy- like motion at the north of the Korea Strait changed into an enclosed anticyclonic eddy of about 200 km in diameter. The Ulleung Eddy became circular shape due to the nonlinear self advection, then changed into elliptical shape in meridional direction because of the blocking effect of the western boundary.

• 한국수산과학회지
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• 제36권2호
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• pp.170-177
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• 2003

This study is to analyze the influence of the Tsushima Warm Current (TWC) on the variation of sound speed in the southern part of the East Sea. Sound speed is calculated by method of Chen and Millero (1977:, based on the CTD data measured in June of 1996. Sound speed in the central part of the TWC is about $45ms^{-1}$ more fast than that in the other regions without the TWC. Sound speed minimum layer (SML) in the TWC region exists between loom and 341 m, while it exists between 260m and 290m in the non-TWC region. SML distributes along the path of TWC over continental shelf in the coastal waters of Japan.

• Ocean and Polar Research
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• 제30권2호
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• pp.193-205
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• 2008

A model of the current and seasonal volume transport in the East China Sea was used to investigate the origin of the Tsushima Warm Current (TSWC). The modeled volume transport field suggested that the current field west of Kyushu ($30^{\circ}-32^{\circ}N$) was divided into two regions, R1 and R2, according to the bottom depth. R1 consisted of the Taiwan Warm Current (TWWC) region and the mixed Kuroshio-TWWC (MKT) water region, while R2 was the modified Kuroshio water (MKW) region west of Kyushu. The MKW branched from the Kuroshio and flowed into the Korea/Tsushima Straits through the Cheju-Kyushu Strait, contributing 41% of the annual mean volume transport of the TSWC. The TWWC and MKT water flowed into the Korea/Tsushima Straits through the Cheju-Kyushu and Cheju Straits, contributing 32% and 27% of the volume transport, respectively. The maximum volume transport of the MKW was 53% of the total volume transport of the TSWC in November, while the maximum volume transport of the water in the R1 region through the Cheju-Kyushu Strait was 41% in July. Hence, there were two peaks per year of volume transport in the TSWC.

• 한국해안해양공학회지
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• 제6권4호
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• pp.364-374
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• 1994

본 연구에서는 순압모델을 이용하여 대마난류(Tsushima Warm Current)의 분기기작 및 계절별 분기위치의 변화에 바람이 미치는 영향을 살펴보았다. 모델 격자간격은 위도와 경로방향 모두 0.25$^{\circ}$로 하였고 해수표면에 적용한 계절별 바람응력은 Hellerman and Rosenstein(1983)의 바람을 이용하였다. 모델결과에 의하면 대마난류는 북풍계열의 바람이 강한 동계(10월-3월)에는 일론 큐슈 남서쪽 대륙사면에서 쿠로시오로부터 직접 분기되어 형성되며, 하계(4월-9월)에는 대만해협(Taiwan Strait)을 통해 유입된 대만난류가 대마난류의 기원으로 나타난다. 쿠로시오는 동계에 최대 수송량을 가지며 하계에 최소를 보이고, 대만난류(Taiwan Current)의 수송량은 이러한 쿠로시오와 약 160도의 위상차를 갖는다. 대마난류의 수송량 변화는 쿠로시오의 변화와 120$^{\circ}$의 위상차(약 4개월)를 가질 때 잘 일치한다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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• pp.89-92
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• 2004

포텐셜와도는 해류의 순환을 설명하는데 유용하게 활용된다. 동해에서 포텐셜와도의 분포 특성을 이용하여 쓰시마난류를 포함한 상층부의 해류순환을 설명하였다. 상층부를 표층부분과 쓰시마난류의 분포 층 그리고 수온약층 분포 수층으로 구분하였다. 극전선남쪽은 쓰시마난류가 해류순환의 중심을 형성하며, 포텐셜와도는 쓰시마난류와 극전선의 분포 특성을 잘 나타내어준다. 포텐셜와도의 분포로부터, 극전선 북쪽은 일본 분지와 그 서쪽해역의 순환 세포로 구분된다.

• 한국해양학회지
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• 제19권2호
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• pp.200-209
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• 1984

1982년 여름에 실시된 해양관측자료에 의하면 대마난류의 흐름은 한국해협 서수도에서 70cm/sec 이상의 강한 표면유속을 갖는 두 개의 분지 형태를 보였다. 부산에서 약 8km 부근에 나타나는 동한 난류로 불리우는 한 개의 분지는 한국 동해안을 따라 북쪽으로 흐르며, 부산으로부터 약 20km 떨어져 나타난 제2분지는 한국해협 통과 후 동쪽으로 향한다. 두 개의 흐름으로 분기되는 현상은 대마난류가 부산-대마도 단면에 이르기 이전에 형성되며, 두 분지의 용적 수송량 및 흐름의 폭은 큰 차이를 보이지 않는다. 분지의 갯수는 서수도의 폭에 의해 좌우되는 듯 하며, 두 분지의 흐름은 층두께의 변화와 서수도와 동해의 폭의 비율과 관련되는 것으로 보인다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권2호
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• pp.91-103
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• 1999

According to numerical experiments, the Sokcho Eddy is produced at $37 5~39.0^{\circ}N$ by strong offshore winds, whereas the Ulleung Eddy is produced at $35~37^{\circ}N$ by an inflow variation of the Tsushima Current. These locations compare well with visual observations. The nonlinear 1$1/2$-layer model showed that most of the East Korea Warm Current (EKWC) driven by the Tsushima Current form the Ulleung Eddy that is larger and stronger than the Sokcho Eddy. In contrast, the nonlinear 2$1/2$-layer model showed that most of the EKWC travels further northward due to a strong subsurface current, thereby enhancing the Sokcho Eddy making it larger and stronger than the Ulleung Eddy. The Sokcho Eddy is also produced relatively offshore due to an eastward subsurface current in the frontal region. Using the 1$1/2$-layer model, when the mass of the Tsushima Current decreases, the two eddies are weakened and produce a circular shape. In the 2$1/2$-layer model the EKWC pushes the Ulleung Eddy northward after 330 days, next the Sokcho and Ulleung eddies begin to interact with each other, and then after 360 days the Ulleung Eddy finally disappears absorbed by the relatively stronger Sokcho Eddy. This behavior compares favorably with other visual observations.

• 한국해양학회지:바다
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• 제24권3호
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• pp.439-447
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• 2019

지금까지의 연구 결과를 토대로 하여 대마난류의 순환역학에 관한 몇 가지 쟁점들을 정리해 보고 향 후 해결할 문제점들을 짚어보는 기회로 삼고자 하였다. 주요 관심 사항은 대마난류의 형성, 그 수송량의 계절변동 및 동해 내부에서의 분지 현상이다. 대마난류는 북태평양 아열대순환의 일부로서 북태평양 전지구적 바람장에 의해 형성된다. 그러나 마찰, 만의 지형, 장벽효과 등에 따라 그 수송량은 민감하게 변한다. 수송량의 계절변동에 대해서는 여러 학자들에 의해 많은 요인들이 제시되어 왔으나 아한대 바람장이 이와 가장 밀접히 연관되어 있는 것으로 밝혀졌다. 그러나 향후, 아한대 바람장 뿐만 아니라 아열대 바람장까지를 포함한 북태평양 전체 바람장과의 관계를 보여줄 수 있는 연구가 필요해 보인다. 대마난류의 두 분지인 동한난류와 일본연안류의 형성 기작으로서 그동안 서안강화 현상과 해저지형 효과가 가장 유력하게 제시되어 왔다. 그러나 서안강화는 동한난류의 계절변동을 설명할 수 없다는 문제점을 갖고 있음으로 이를 대체할 다른 기작에 대한 연구가 필요하다고 사료된다.

• Fisheries and Aquatic Sciences
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• 제5권3호
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• pp.219-228
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• 2002

Based on the five-year (October 1992 through September 1997) Topex/Poseidon altimeter measurements, we describe the statistical characteristics of the eddy variability in the East Sea in terms of sea surface height anomaly, slope variability, and eddy kinetic energy (EKE). The sea surface height anomalies in the East Sea are produced with standard corrections from Topex/Poseidon measurements. In order to eliminate the high frequency noise in the sea surface height anomaly data, the alongtrack height anomaly data was filtered by about 40 km low-pass Lanczos filter based on Strub et al. (1997) and Kelly et a1. (1998). We find that there exists a distinct spatial contrast of high eddy variability in the south and low eddy energy in the north, bordering the Polar Front. In the northwestern area $(north\;of\;39^{\circ}N\;and\;west\;of\;133^{\circ}E)$ from the Polar Front where the eddies frequently appear, the EKE is also considerabel. The high kinetic energy in the southern East Sea reveals a close connection with the paths of the Tsushima Warm Current, suggesting that the high variability in the south is mainly generated by the baroclinic instability process of the Tsushima Warm Current. This finding is supported by other studies (Fu and Zlontnicki, 1989; Stammer, 1997) wh.ch have shown the strong eddy energy coupled in the major current system. The monthly variation of the EKE in both areas of high and low eddy variability shows a strong seasonality of a high eddy kinetic energy from October to February and a relatively low one from March to September. The sequential pattern of wind stress curl shows resemblance with those of monthly and seasonal EKE and the two sequences have a correlation of 0.82 and 0.67, respectively, providing an evidence that wind stress curl can be the possible forcing for the monthly and seasonal variation of the EKE in the East Sea. The seasonality of the EKE also seems to correlate with the seasonality of the Tsushima Warm Current. There also exists the large spatial and interannual variabilities in the EKE.