• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.1-14
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• 2023

High-Frequency Radar (HF-Radar) data of surface currents in Yeongil Bay (a semi-enclosed sea area of the East Sea) was used to investigate the between wind and horizontal surface currents The variation in horizontal and vertical flow of surface currents correlated closely to the water temperature time-series data of densely spaced (1 to 2 m) layers. During the time-series observation period, when the northeast wind prevailed over the entire Yeongil Bay area, a rapid rise in water temperature was recorded across all the layers. Moreover, currents parallel to the wind direction were clearly observed in low-frequency currents of the surface layer. Time-delayed correlation analysis between wind and surface current confirmed that if northeasterly wind blows in Yeongil Bay and continues unidirectionally, a southwestward surface current occured within a short period of time (1 to 2 hours). Convergence and divergence were calculated from the daily average values of low-frequency surface currents. A rapid rise in temperature occurred in the lower layers of water at the observation points, due to the convergence (downwelling) of the surface seawater (relatively high temperature water) associated with the northeasterly wind.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.2
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• pp.99-108
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• 2014

One year long time-series current data were obtained at two stations (K1 and K2) located in the Usan Trough in the area north of Ulleungdo in the East Sea from September 2006. The observed data reveal enhanced seafloor flows in both stations with variabilities of about 20 days which is possibly governed by the topographic Rossby wave. After February 2007, strong flow in the upper layer in St. K1 appears throughout the mooring period and this is due to the passage of the warm eddy comparing with satellite sea surface temperature data. During this period, no significant correlation between the current in the upper layer and those in two deep layers is shown indicating the eddy does not affect flows in the deep ocean. It is also observed that the flow direction rotates clockwise with depth in both stations except for the upper of the K1. This implies that the deep flow does not parallel to the isobaths exactly and it has a downwelling velocity component. The possibility of the flow from the Japan Basin to the Ulleung Basin across the Usan Trough is not evidenced from the data.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.53-54
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• 2010

국내에서 소규모 어항의 재개발에 관광객 유치를 위한 친환경적인 기술의 적용이 본격화되고 있다. 항내수질 개선이라는 목적 하에서 외곽시설인 방파제의 선택은 항내 정온과 제체 안정성의 확보가 전제되어야 한다. 따라서 본 연구에서는 친환경방파제인 슬릿방파제의 수리특성을 파악하기 위한 수리모형실험을 수행하고 그 결과를 이용하여 파랑변형 및 유동 실험을 수행하였다. 현장 적용성 확인을 위하여 선정된 구조라항은 우리나라 남해의 소규모 어항으로, SSE, S, SSW파향에 영향을 받는 지역으로, 슬릿방파제를 적용한 결과 제체안정성과 항내 정온도가 확보되는 것으로 나타났다. 이는 슬릿방파제의 특징으로 장주기파의 통과율이 뛰어나다는 점과 소파효과라는 1차적인 목적과 항만 및 연안수역에서 해수교환의 향상이라는 2차적인 목적을 동시에 만족하는 것으로 나타났다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.1
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• pp.43-52
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• 2006

Numerical model tests are done in order to evaluate impact zone of low salinity water on outer region of the developing Saemankeum reservoir. Also saline mixing processes are investigated f3r the inner reservoir with consideration of Mankyoung and Donjin riverine flood discharges when sea water is passing freely through gate. In these analyses 2-d ADCIRC, 3-d TIDED3D and CE-QUAL-ICM models are used. Through models tests, it is found that inner reservoir mixing process caused by inflow of outer sea water occurs gradually. It takes at least one month for complete mixing on Mankyoung part and 6 month on Dongjin part of the reservoir. When Sinsi or Garyeok gates are opened to control inner reservoir level, discharging velocities decrease exponentially from the gates, but show very strong currents of 0.5m/sec to the 10Km region apart. These results imply that hydrodynamic circulation and ecosystem of frontal region of the Saemankeum dike might be affected in amount by gate operations, since low saline inner waters are discharged periodically at ebb tide according to tidal level.