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This study aimed to investigate the heavy metals distribution in the surrounding area of green mussel culture net, Cilincing water, Jakarta Bay, and its distribution behavior. The water sampling was carried out during the ebb tide. The heavy metal concentration was then measured by using atomic absorption spectroscopy (AAS). In order to understand the water circulation behavior related to heavy metal distribution in the study area, the Princeton Ocean Model was applied, and the model design was developed based on a scenario of an open canal in the eastern and western sides, while the center canal was placed with net cages in the water column resembling the green mussel culture net. The observed heavy metal distribution showed an intensified concentration in the green mussel culture location. The observed water current also showed a reduced velocity in the location. The modeling approach could explain the water circulation behavior in response to the presence of net units in the water column. In this case, the density of net units for green mussel culture potentially produced shear stress in the water column, which affected the flow pattern and the distribution of heavy metals. Therefore, the existence of green mussel culture nets has a potential to become a trap for pollutant distribution in the water.

With consideration of the comprehensive effects of runoff from the Yangtze River, East China Sea background circulation, and tidal currents, a regional circulation model, including the Yangtze Estuary, Hangzhou Bay, and adjacent sea areas was established. The 2002/2003 El Niño event was chosen for study of the anomalies of circulation outside the Yangtze Estuary. The coastal and ocean current systems of the East China Sea and the current structure outside the Yangtze Estuary were accurately described. The results of vertical circulation analysis basically coincide with those of horizontal circulation analysis, showing that the circulation outside the Yangtze Estuary is mainly affected by the Taiwan warm current, runoff from the Yangtze Estuary, and the tide-induced residual current. The El Niño event weakens Yangtze Estuary circulation to a certain degree, and the impacts are more significant in summer than in winter. During the 2002/2003 El Niño event, the flux of the Taiwan warm current decreases, and the northward component of the Taiwan warm current decreases by half in February 2003 compared to the previous year. However, its path is relatively stable.

The impact of cold discharge (CD) released from Tongyeong LNG terminal was evaluated at different flow rates. At the actual flow rate of 10 m3 s−1, the impact of CD on surrounding seawaters was insignificant with a slight decrease in seawater temperature. The surface and bottom seawater temperature within a 1 km radius from the discharge outlet decreased by an average of 0.4 °C and 0.6 °C, respectively. At a simulation flow rate of 500 m3 s−1, CD settled to the bottom and widely diffused. The seawater temperature within a 1 km radius from the discharge outlet decreased by an average of 3.1 °C and 5.2 °C in the surface and bottom layers, respectively. A machine learning-based model was trained to estimate the diffusion area of CD using physical factors at the outlet as predictors. The trained model could identify not only the optimal sites of the LNG terminal to minimize the impact of CD on the surrounding seawaters but also worst-case site. This CD modeling process could enable low-cost impact assessments on seawaters, and the same process could be used for thermal discharge. • Cold discharge in the bottom diffused more than that in the surface layer. • Stratification strength near the outlet increased due to the cold discharge. • Diffusion area of cold discharge can be modeled using physical factors at the outlet. • Cold discharge modeling could identify the optimal sites of LNG terminal. [ABSTRACT FROM AUTHOR]

The oil spill risk analysis (OSRA) model is a tool used by the Bureau of Ocean Energy Management (BOEM) to evaluate oil spill risks to biological, physical, and socioeconomic resources that could be exposed to oil spill contact from oil and gas leasing, exploration, or development on the U.S. Outer Continental Shelf (OCS). Using long-term hindcast winds and ocean currents, the OSRA model generates hundreds of thousands of trajectories from hypothetical oil spill locations and derives the probability of contact to these environmental resources in the U.S. OCS. This study generates probability of oil spill contact maps by initiating trajectories from hypothetical oil spill points over the entire planning areas in the U.S. Gulf of Mexico (GOM) OCS and tabulating the contacts over the entire waters in the GOM. Therefore, a probability of oil spill contact database that stores information of the spill points and contacts can be created for a given set of wind and current data such that the probability of oil spill contact to any environmental resources from future leasing areas can be estimated without a rerun of the OSRA model. The method can be applied to other OCS regions and help improve BOEM’s decision-making process.

A typhoon-driven upwelling event was observed with coastal acoustic tomography in Hiroshima Bay during September 2013. The tomography data were used to obtain state estimates from an ocean model, employing the ensemble Kalman filter (EnKF) for data assimilation. Hiroshima Bay was represented as a two-layer system with a fresh, near-surface layer overlaying a more saline, lower layer. Wind from the typhoon forced the surface layer southward, thus drawing the lower layer northward and causing upwelling. After the upwelling, these currents reversed for a period. During the upwelling, the total volume transports for the upper and lower layers were well balanced, showing continuity of the two layers. However, the total upper layer volume transported northward during the reverse-flow period was significantly smaller than the total upper layer volume transported southward during the upwelling, and significantly larger than the total lower layer volume transported southward during the reverse-flow period. The downstream reductions of transported volume indicated mixing fractions of 24%-30%, with water mixing at the interface of the upper and lower layers. Errors in state estimates were less than the changes in current and salinity associated with the upwelling. [ABSTRACT FROM AUTHOR]

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Numerical simulation experiments with a high-resolution circulation model were carried out to study nutrient transport from different depths to the surface 10-m layer during an upwelling event along the northern coast of the Gulf of Finland in July 1999. The initial nutrient distribution is based on field measurements performed in the north-western part of the Gulf. Wind forcing covering the period of the upwelling along the northern coast was turned through 180° to simulate an upwelling along the southern coast. The simulation results showed that the main phosphorus transport to the upper 10-m layer occurred from depths shallower than 30 m for the upwelling events along both the northern and the southern coasts. Nitrogen transport to the upper 10-m layer was the largest from depths of 40-55 m for the upwelling along the northern and 40-65 m for the upwelling along the southern coast. Simulated cumulative volume transports to the upper 10-m layer from different depths showed that the contribution from deeper layers was larger in the case of the upwelling along the southern coast. The reduction of wind stress had a bigger influence on water transport from the deeper layers.

Göl ve haznelerdeki akıntı yapısı birçok dış etkene bağlı olarak değişmektedir. Oluşan akıntı yapısını gölün tüm noktalarında yerinde ölçümle belirlemek oldukça masraflı ve zordur. Bu nedenle, hızları ve seviye değişimlerini bilgisayar ortamında belirleyen modeller geliştirilmiştir. Bu modeller kullanılarak, oluşabilecek çevresel sorunların önceden tahmin edilebilmesi ve su kirlilik konsantrasyonlarının belirlenmesi için bir altyapı elde edilmiş olur. Günümüzde göl ve haznelerin modellenmesinde üç boyutlu modellerin kullanımı yaygınlaşmıştır. Bu çalışmada, Denizli'de bulunan Gökpınar Baraj Gölü için Princeton Okyanus Modeli (POM) ile yapılmış olan üç boyutlu hidrodinamik modellemenin sonuçları üzerinde Yapay Sinir Ağları (YSA) modeli uygulanarak göl içindeki bazı kesitler için çeşitli rüzgar yön ve hızları altında oluşan hız ve seviye değişimi değerleri elde edilmiştir. Oluşturulan YSA modeli, aynı kesitlere farklı rüzgar şartları altında tekrar uygulanmış ve sonuçların POM sonuçlarına uyum gösterdiği tespit edilmiştir. Yapılan karşılaştırmalar neticesinde, model oluşturulması ve çözüm aşamalarında her iki yöntemin birbirine üstünlük sağladığı unsurlar tespit edilmiş ve belirtilmiştir.

Göl ve haznelerdeki akıntı yapısı birçok dış etkene bağlı olarak değişmektedir. Oluşan akıntı yapısını gölün tüm noktalarında yerinde ölçümle belirlemek oldukça masraflı ve zordur. Bu nedenle, hızları ve seviye değişimlerini bilgisayar ortamında belirleyen modeller geliştirilmiştir. Bu modeller kullanılarak, oluşabilecek çevresel sorunların önceden tahmin edilebilmesi ve su kirlilik konsantrasyonlarının belirlenmesi için bir altyapı elde edilmiş olur. Günümüzde göl ve haznelerin modellenmesinde üç boyutlu modellerin kullanımı yaygınlaşmıştır. Bu çalışmada, Denizli'de bulunan Gökpınar Baraj Gölü için Princeton Okyanus Modeli (POM) ile yapılmış olan üç boyutlu hidrodinamik modellemenin sonuçları üzerinde Yapay Sinir Ağları (YSA) modeli uygulanarak göl içindeki bazı kesitler için çeşitli rüzgar yön ve hızları altında oluşan hız ve seviye değişimi değerleri elde edilmiştir. Oluşturulan YSA modeli, aynı kesitlere farklı rüzgar şartları altında tekrar uygulanmış ve sonuçların POM sonuçlarına uyum gösterdiği tespit edilmiştir. Yapılan karşılaştırmalar neticesinde, model oluşturulması ve çözüm aşamalarında her iki yöntemin birbirine üstünlük sağladığı unsurlar tespit edilmiş ve belirtilmiştir.

The Rio de la Plata, one of the largest rivers on Earth, discharges into the ocean waters from basin that covers a large area of South America. Its plume extends along northern Argentina, Uruguay, and southern Brazil shelves strongly influencing the ecosystems. In spite of this, little is known about the mechanisms that control it. Here we report results of simulations with POM carried out to investigate the roles of wind and river discharge in Plata plume dynamics. Different outflows were explored, including an average climatological value and magnitudes representative of La Niña and El Niño. Forcing the model with river discharge the average plume speed was directly related to the outflow intensity. The Plata northward extension varied from 850 to 1550 km and for average discharge a band of low salinity waters formed from the estuary up to 30ºN of South Brazilian Shelf. Upwelling and downwelling winds were applied after 130 days. The distribution of low salinity waters over the shelf was more sensitive to the wind direction than to the river outflow variability. Downwelling winds were very capable of advecting the low salinity signal downshelf. Upwelling winds were efficient in eroding the plume, which was basically detached from the coast by Ekman drift. Abnormal plume intrusions toward low latitudes may be a result of the original plume position coupled with events of persistent strong downwelling favorable winds.O Rio da Prata, um dos maiores rios da Terra, descarrega no oceano águas de uma bacia de drenagem que cobre uma ampla área da América do Sul. Sua pluma extende-se ao longo do norte da Argentina, Uruguay e sul do Brasil influenciando amplamente os ecossistemas costeiros. A despeito disso, pouco se sabe a respeito dos mecanismos que a controlam. Relatamos aqui simulações conduzidas com o modelo POM na investigação do papel dos ventos e da descarga fluvial na dinâmica da pluma do Prata. Descargas com valores médios climatológicos e magnitudes representativas de El Niño e La Niña foram explorados. Somente sob descarga fluvial, a velocidade média de penetração da pluma ao longo da costa foi diretamente relacionada à vazão. Sua extensão variou entre 850 e 1550 km e no caso da vazão média uma banda de baixa salinidade formou-se desde o estuário até 30ºN na plataforma continental sul brasileira. O efeito de ventos de sudoeste, que causam subsidência, e de nordeste, que promovem a ressurgência costeira, foram investigados após 130 dias de descarga fluvial. Os resultados sugerem que a distribuição de baixa salinidade é muito mais sensível à direção dos ventos do que à descarga fluvial. Ventos de sudoeste são capazes de advectar o sinal de baixa salinidade ao longo da costa. Já os ventos de nordeste demonstram ser eficientes na erosão da pluma, que é destacada da costa por deriva de Ekman. Uma intrusão anormal da pluma de baixa salinidade em direção a baixas latitudes pode ser o resultado da posição original da pluma acoplada a eventos persistentes de fortes ventos de sudoeste.

Tropical coastal areas are sensitive ecosystems to climate change, mainly due to sea level rise and increasing water temperatures. Furthermore, they may be subject to numerous stresses, including heat releases from energy production. The Urias coastal lagoon (SE Gulf of California), a subtropical tidal estuary, receives cooling water releases from a thermoelectric power plant, urban and industrial wastes, and shrimp farm discharges. In order to evaluate the plant thermal impact, we measured synchronous temperature time series close to and far from the plant. Furthermore, in order to discriminate the thermal pollution impact from natural variability, we used a high-resolution hydrodynamic model forced by, amongst others, cooling water release as a continuous flow (7.78 m s) at 6 °C overheating temperature. Model results and field data indicated that the main thermal impact was temporally restricted to the warmest months, spatially restricted to the surface layers (above 0.6 m) and distributed along the shoreline within ∼100 m of the release point. The methodology and results of this study can be extrapolated to tropical coastal lagoons that receive heat discharges. [ABSTRACT FROM AUTHOR]

A numerical model is used to gauge the impact of winds on the evolution of coastal plumes generated by a variety of inlet outflows. The analysis is summarized by a conceptual model that accounts for the formation of surface and bottom mixed layers and tilting of the plume front. It also provides the basis for a two parameter classification of upwelling. The first parameter indicates when a wind event is capable of fully exporting plume waters offshore. The second determines when winds can overcome the plume buoyancy-driven flow. These indices help to explain why larger outflows tend to be less susceptible to upwelling. During an upwelling event, large plumes tend to maintain their structure, while smaller systems are commonly detached and dispersed offshore. The onset of downwelling events often reorganizes large plumes, thus promoting their net downshelf displacement. In contrast smaller systems frequently restart their formation, consequently limiting their downshelf penetration. The addition of long-term fluctuations, superimposed to the synoptic wind forcing, suggests a mechanism for typical seasonal to interannual variability commonly observed for large discharges. [ABSTRACT FROM AUTHOR]

The Princeton Ocean Model (POM) was modified to simulate motion of a group of particles floating on the sea surface in the Gulf of Thailand. The particles in this group were set up so that they formed a circle. The radius reflected uncertainties of longitude and latitude directions while the centre was set at the point of interest. POM was incorporated with tidal forcing on the boundary, which included used current forcing on the inflow by wind velocities, high resolution and realistic ocean bottom topography, temperature and salinity. The model domain for the Gulf of Thailand extended from latitude 3°N-14°N and longitude 99°E-109°E. A horizontal grid resolution of 0.1 degree (approximately 11.1 km) was used in the model. Therefore, the grids consisted of 101×111 cells. Twenty one levels in sigma coordinate were used in vertical resolution. The model results were verified using TOPEX/Poseidon and JASON satellite data. The results of the simulation were used to gain a better understanding of the sea current and object movement patterns in the Gulf of Thailand.

The objective of this work is to present the implementation of a circulation modeling system for the northwestern area of the Black Sea. In this regard, two simulations using Mohid water modeling system were performed for the months of February and August 2010. The input data considered for the current simulations are salinity and temperature fields, obtained from the Black Sea Forecast System, coastlines, bathymetry from ETOPO2 website and wind forcing provided by the European Centre for Medium Range Weather Forecasts (ECMWF). Model validations were performed considering satellite data. Moreover, the simulation results were compared to an implementation of the Princeton Ocean Model (POM) realized by the National Institute for Marine Research and Development "Grigore Antipa". [ABSTRACT FROM AUTHOR]

A data-assimilated Taiwan Ocean Prediction (ATOP) system is being developed at the National Central University, Taiwan. The model simulates sea-surface height, three-dimensional currents, temperature and salinity and turbulent mixing. The model has options for tracer and particle-tracking algorithms, as well as for wave-induced Stokes drift and wave-enhanced mixing and bottom drag. Two different forecast domains have been tested: a large-grid domain that encompasses the entire North Pacific Ocean at 0.1° x 0.1° horizontal resolution and 41 vertical sigma levels, and a smaller western North Pacific domain which at present also has the same horizontal resolution. In both domains, 25-year spin-up runs from 1988 - 2011 were first conducted, forced by six-hourly Cross-Calibrated Multi-Platform (CCMP) and NCEP reanalysis Global Forecast System (GSF) winds. The results are then used as initial conditions to conduct ocean analyses from January 2012 through February 2012, when updated hindcasts and real-time forecasts begin using the GFS winds. This paper describes the ATOP system and compares the forecast results against satellite altimetry data for assessing model skills. The model results are also shown to compare well with observations of (I) the Kuroshio intrusion in the northern South China Sea, and (ii) subtropical counter current. Review and comparison with other models in the literature of "(I)" are also given. [ABSTRACT FROM AUTHOR]

Prediction of mixing intensity of water masses in riverine Lake Tegel (Berlin, Germany) can be used to trace the fate of pollutants that enter the lake through several inflows. Because the contributions of each inflow have not yet been quantified and because the lake features complex bathymetry and numerous islands, a hydrodynamic circulation model with high spatial resolution and dynamic wind forcing is useful. We applied the two-dimensional version of the Princeton Ocean Model to separate the influences of wind and river discharge on the currents and mass transport in Lake Tegel. For model validation, we compared the simulation results with 1 year of electrical conductivity data, which was used as a conservative tracer to distinguish between water from the River Havel and water supplied by a smaller second inflow. Calculation of currents alone is insufficient to investigate water exchanges between rivers and lakes, especially when several islands create multiple pathways for river intrusion. Therefore, mass transport simulations are applied. Our calculations based on archetypical scenarios indicate that the proportion of (polluted) water from the River Havel in the main basin of Lake Tegel fluctuates with river discharge and wind, which either amplify or neutralize each other. [ABSTRACT FROM AUTHOR]

An observational and numerical (Princeton Ocean Model) study of the summer thermocline development in the Persian Gulf (PG) shows that as the northwesterly cold winter wind weakens and become warmer, the fresher inflow from Oman Sea penetrates much further into the PG. This is also associated with stronger solar radiation leading to the near surface thermocline development over the whole of the PG. For more realistic monthly averaged wind, the thermocline develops as is indicated by observations. This is particularly marked in the deeper central part in which it grows in depth about 0.2(m) per day. The formation of thermocline decreases the dissolved oxygen in water column due to induced stratification. Over the PG the temperature difference between surface and subsurface increases exponentially from March until May when it levels off, with similar smaller variations for salinity differences than observed. [ABSTRACT FROM AUTHOR]

Abstract: The International Nusantara Stratification and Transport (INSTANT) program measured currents through multiple Indonesian Seas passages simultaneously over a three-year period (from January 2004 to December 2006). The Indonesian Seas region has presented numerous challenges for numerical modelers — the Indonesian Throughflow (ITF) must pass over shallow sills, into deep basins, and through narrow constrictions on its way from the Pacific to the Indian Ocean. As an important region in the global climate puzzle, a number of models have been used to try and best simulate this throughflow. In an attempt to validate our model, we present a comparison between the transports calculated from our model and those calculated from the INSTANT in situ measurements at five passages within the Indonesian Seas (Labani Channel, Lifamatola Passage, Lombok Strait, Ombai Strait, and Timor Passage). Our Princeton Ocean Model (POM) based regional Indonesian Seas model was originally developed to analyze the influence of bottom topography on the temperature and salinity distributions in the Indonesian seas region, to disclose the path of the South Pacific Water from the continuation of the New Guinea Coastal Current entering the region of interest up to the Lifamatola Passage, and to assess the role of the pressure head in driving the ITF and in determining its total transport. Previous studies found that this model reasonably represents the general long-term flow (seasons) through this region. The INSTANT transports were compared to the results of this regional model over multiple timescales. Overall trends are somewhat represented but changes on timescales shorter than seasonal (three months) and longer than annual were not considered in our model. Normal velocities through each passage during every season are plotted. Daily volume transports and transport-weighted temperature and salinity are plotted and seasonal averages are tabulated. [Copyright &y& Elsevier]

The spatial structures and propagation characteristics of coastal trapped waves (CTWs) along the southern and eastern coasts of Australia are investigated using observed daily mean sea level data and results from a high-resolution ocean general circulation model (OGCM), and by conducting sensitivity studies with idealized numerical models. The results obtained from the sea level observations show that shortterm variations, with a typical period of 1 to 2 weeks, dominate the sea level variability in the southern half of Australia. The signal propagates anticlockwise around Australia with a propagation speed of 4.5 m/s or faster in the western and southern coasts and 2.1 to 3.6 m/s in the eastern coast. Strong seasonality of the wave activity, with large amplitude during austral winter, is also observed. It turns out that the waves are mainly generated by synoptic weather disturbances in the southwestern and southeastern regions. The numerical experiment with idealized wind forcing and realistic topography confirms that the propagating signals have characteristics of the CTW both in the southern and eastern coasts. Sensitivity experiments demonstrate that the difference in the phase speed between the coasts and reduction of the amplitude of the waves in the eastern coast are attributed to the different shape of the continental shelf in each region. The structures and the propagation characteristics of the CTWs around Australia are well reproduced in OFES (OGCM for the Earth Simulator) with dominant contribution from the first mode, although meso-scale eddies may modify the structure of the CTWs in the eastern coast. It is also found that generation or reinforcement of the waves by the wind forcing in the southern part of the eastern coast is necessary to obtain realistically large amplitude of the CTWs in the eastern coast. [ABSTRACT FROM AUTHOR]

We present a method for assimilating current observations into a two-dimensional circulation model of Lake Michigan, based on the Princeton Ocean Model (POM) and driven by observed winds. Because measurements of surface level are not available, we require that the point-wise update to the forecast horizontal current does not change the forecast surface level. This requirement makes it possible to represent the current updates by a stream function. Given an appropriate covariance model of this stream function, the current updates are calculated by kriging interpolation using the observations and the corresponding model forecast. It is further required that the current updates do not create cross-shore flows; this is represented by the stream function being constant along the coastline and is enforced by incorporating pseudo coastal data into the interpolation. This eliminates the need to construct complex spatial covariance models for the stream function. The method also accommodates observational errors. Results show that the method successfully melds observations into the model, and the influence of data assimilation propagates in space and time. [ABSTRACT FROM AUTHOR]