• Journal of Ocean Engineering and Technology
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• v.17 no.2
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• pp.1-7
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• 2003

A common feature in the three-dimensional numerical model experiments of coastal discharge with simplifed model and idealized external forcings is investigated. The velocity fields due to the buoyancy and flow flux, are spreaded radiately and the surface velocites are much greater than homegeneous discharges. The coastal dischargd due to the Coriolis force and flow flux are shaped a anticyclical gyre (clockwise) and determined the scale of the gyre in the coastal zone, respectively. The bottom topography restricts a outward extention of the coastal fronts and it accelerates a southward flow.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.1
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• pp.59-69
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• 2013

Temporal and spatial variation in the freshwater region, created by river runoff, of a small bay, caused by the passage of typhoons was examined using a three-dimensional primitive equation model (the Princeton Ocean Model, POM). Numerical experiments were implemented focusing on temporal evolution in the freshwater region in association with typhoon tracks. The model domain covered most of the estuary around the Nakdong River, including Noksan Bay, where river water is periodically released from upstream (Noksan dam). The model showed that the extension of the freshwater region outside of the bay depended strongly on the tracks of typhoons, specifically the associated wind directions and inner flow fields that are accompanied by new clockwise eddies. The model also showed that entrainment from typhoon passage frequently creates salt wedges in the estuary, indicating that organisms in the bay are biologically and chemically influenced with variation in the freshwater region.

• Journal of Environmental Science International
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• v.23 no.3
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• pp.459-472
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• 2014

Storm surge height in the coastal area of Jeju Island was examined using the Princeton Ocean Model(POM) with a sigma coordinate system. Amongst the typhoons that had affected to Jeju Island for six years(1987 to 2003), the eight typhoons(Maemi, Rusa, Prapiroon, Olga, Yanni, Janis, Gladys and Thelma) were found to bring relatively huge damage. The storm surge height of these typhoons simulated in Jeju harbour and Seogwipo harbour corresponded relatively well with the observed value. The occurrence time of the storm surge height was different, but mostly, it was a little later than the observed time. Jeju harbour showed a higher storm surge height than Seogwipo harbour, and the storm surge height didn't exceed 1m in both of Jeju harbour and Seogwipo harbour. Maemi out of the eight typhoons showed the maximum storm surge height(77.97 cm) in Jeju harbour, and Janis showed the lowest storm surge height(5.3 cm) in Seogwipo harbour.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.187-190
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• 2003

한반도 서남부해역은 하계 양자강의 방류에 의해 저염분 현상이 발생한다. 양자강 방류량은 해마다 일정하지 않으며, 과거 시계열자료에 의하면 최대값이 최소값보다 2배 이상이 됨을 알 수 있다. 다라서 양자강의 방류량을 달리하여 저염분포를 수치모델로 연구하고자 하였다. 수치모델은 POM(Princeton Ocean Model)을 사용하였다. POM은 연직적으로 $\sigma$-좌표계를 사용하는 3차원 순환모델이다. 모델 수행 후 연구해역내 대륙사면부에서 유속이 강하게 나타남을 알 수 있다. 또한 제주도 서쪽을 통해 북상하여 황해중앙부로 들어가는 흐름이 있으며, 대륙연안을 따라 남하하는 흐름이 있음을 알 수 있다 양자강 방류량을 부여한 수행한 모델의 결과를 보면 양자강 방류량이 많을수록 저염분역이 제주도에 가깝게 나타남을 랄 수 있다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.137-147
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• 2004

Sea surface cooling (SSC) with the passage of typhoons is examined in the East Sea using the Japan Meteorological Agency buoy data $(37^{\circ}45'N,\;134^{\circ}23'E)$ during 1983-2000 and a three-dimensional primitive equation model (the Princeton Ocean Model). Forty typhoons in this period induced the SST decrease ranging from about $-0.5^{\circ}C\;to\;-4.3^{\circ}C.$ Intense SSC $(<-2^{\circ}C)$ occurs with typhoons that passed mainly through the left-hand side of the buoy station. The model is implemented to examine a physical process of SSC with a typical-track typhoon in the northwestern Pacific $(24^{\circ}N\;to\;52^{\circ}N).$ The model well reproduces prominent features in the observation and addresses how it happens; SSC is induced mainly by momentum mixing effect stirred with the typhoon rather than upwelling.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.549-561
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• 2003

Behavior of the Nakdong River plume was studied by the analysis of the observed CTD data and numerical simulations using three-dimensional Princeton Ocean model (POM) in which the river discharge, tides and winds were considered. During the flood season of summer the 30 psu isohaline expands northward to Daebyeon and southwestward to Samcheonpo. The model results show that the isohalines are approximately parallel to the bottom slope, which suggests the possibility of upwelling induced by the topographic effects. Northwesterly wind expands the river plume to the offshore direction so that the inflow of fresh plume water into Jinhae Bay through the Gaduk Channel is constrained, then the coastal upwelling seems to be caused by the wind-driven current at the southern edge of Gaduk Island. Southwesterly wind expands the river plume toward Daebyeon, and the inflow of fresh water into Jinhae Bay is also constrained.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.4
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• pp.295-307
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• 2012

In order to understand the flow properties of the South Sea of Korea, tidal currents, wind-driven currents, density-driven currents and residual flows were investigated by using 3-dimensional numerical model(POM). In offshore regions, tide-induced residual current tends to flow eastward during the spring tide and westward during the neap tide. Total residual flow is irregular due to the bottom topography in the coastal area. The density-driven currents in the coastal area showed to be relatively weak, with little seasonal differences. The special tendency was apparent in the open sea. That is, the flow in the offshore regions showed results similar to that of the Tsushima current. The wind-driven currents in the coastal area showed to be much stronger than in offshore regions. Vertically, the flow of the surface layer was much stronger than that of the bottom layer. Through these results, material transport and diffusion in the south coast, as a basis for predicting the spread of use is expected to be available.

• Journal of Ocean Engineering and Technology
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• v.21 no.6
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• pp.87-94
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• 2007

This study used POM (Princeton ocean model) improved for applying to coastal area in order to predict the distribution of thermal waste water. This model was applied to the coastal circulation and the effect of thermal waste water of Cheonsu-Bay. So this study compared the discharge of thermal waste water with each layer and section. The tidal current was about 1.5 m/sec at surface level and 0.9 m/sec on bottom level at flood tide; tidal current was about 1.3 m/sec on surface level and 0.8 m/sec on bottom level at ebb tide. The method discharging the thermal waste water in the nearshore region (case 1) accelerates the diffusion of the thermal waste water in the north-south direction(longshore direction). However, the method discharge the thermal waster water in the offshore region (case 2) reduced the diffusion of the thermal waste water over the coastal region. According th the diffusion region of the thermal waste water with case 1 and case 2 at three different layers (surface, middle, bottom), the diffusion region by case 1 discharge method generally influenced wider region (twice) than the one by case 2 discharge method with lower temperature between $1^{\circ}C\;and\;2^{\circ}C$, whereas the case 2 discharge method influenced the deeper region (middle and botton layers) with higher change of the water temperature ($1{\sim}3^{\circ}C$).

• Journal of the korean society of oceanography
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• v.39 no.2
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• pp.119-135
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• 2004

A three-dimensional numerical model using POM (the Princeton Ocean Model) is established in order to understand the dispersion processes of the Yangtze River water in the Yellow and East China Seas. The circulation experiments for the seas are conducted first, and then on the bases of the results the dispersion experiments for the river water are executed. For the experiments, we focus on the tide effects and wind effects on the processes. Four cases of systematic experiments are conducted. They comprise the followings: a reference case with no tide and no wind, of tide only, of wind only, and of both tide and wind. Throughout this study, monthly mean values are used for the Kuroshio Current input in the southern boundary of the model domain, for the transport through the Korea Strait, for the river discharge, for the sea surface wind, and for the heat exchange rate across the air-sea interface. From the experiments, we obtained the following results. The circulation of the seas in winter is dependent on the very strong monsoon wind as several previous studies reported. The wintertime dispersion of the Yangtze River water follows the circulation pattern flowing southward along the east coast of China due to the strong monsoon wind. Some observed salinity distributions support these calculation results. In summertime, generally, low-salinity water from the river tends to spread southward and eastward as a result of energetic vertical mixing processes due to the strong tidal current, and to spread more eastward due to the southerly wind. The tide effect for the circulation and dispersion of the river water near the river mouth is a dominant factor, but the southerly wind is still also a considerable factor. Due to both effects, two major flow directions appear near the river mouth. One of them is a northern branch flow in the northeast area of the river mouth moving eastward mainly due to the weakened southerly wind. The other is a southern branch flow directed toward the southeastern area off the river mouth mostly caused by tide and wind effects. In this case, however, the tide effect is more dominant than the wind effect. The distribution of the low salinity water follows the circulation pattern fairly well.

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.167-181
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• 2010

To predict changes in the marine environment of the Beolgyo Stream Estuary in Jeonnam Province, South Korea, where cohesive tidal flats cover a broad area and a large bridge is under construction, this study conducted numerical simulations involving tidal flow and cohesive sediment transport. A wetting and drying (WAD) technique for tidal flats from the Princeton Ocean Model (POM) was applied to a large-scale-grid hydrodynamic module capable of evaluating the flow resistance of structures. Derivation of the eddy viscosity coefficient for wakes created by structures was accomplished through the explicit use of shear velocity and Chezy's average velocity. Furthermore, various field observations, including of tide, tidal flow, suspended sediment concentrations, bottom sediments, and water depth, were performed to verify the model and obtain input data for it. In particular, geologic parameters related to the evaluation of settling velocity and critical shear stresses for erosion and deposition were observed, and numerical tests for the representation of suspended sediment concentrations were performed to determine proper values for the empirical coefficients in the sediment transport module. According to the simulation results, the velocity variation was particularly prominent around the piers in the tidal channel. Erosion occurred mainly along the tidal channels near the piers, where bridge structures reduced the flow cross section, creating strong flow. In contrast, in the rear area of the structure, where the flow was relatively weak due to the formation of eddies, deposition and moderated erosion were predicted. In estuaries and coastal waters, changes in the flow environment caused by artificial structures can produce changes in the sedimentary environment, which in turn can affect the local marine ecosystem. The numerical model proposed in this study will enable systematic prediction of changes to flow and sedimentary environments caused by the construction of artificial structures.