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Co-tidal chart of the model-predicted M 2 tidal elevation. Heavy solid line: Co-amplitude (cm) and thin solid line: co-phase (°G).
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1] The tidal motion in Mt. Hope Bay (MHB) and Narragansett Bay (NB) is simulated using the unstructured grid, finite-volume coastal ocean model (FVCOM). With an accurate geometric representation of irregular coastlines and islands and sufficiently high horizontal resolution in narrow channels, FVCOM provides an accurate simulation of the tidal wave...
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Context 1
... A tidal-induced inertial-gravity wave propagates into the NB-MHB from the inner shelf with a dominant fre- quency at the M 2 tidal constituent. The model-predicted M 2 co-tidal chart shows that co-amplitude lines are generally laid across the bay with a slight shift to the southeast- northwest direction ( Figure 3). This indicates that at the same latitude, the tidal elevation is slightly higher on the right side of the bay than on the left side of the bay. ...
Context 2
... The interaction of tidal flushing in the MHB-NB and MHB-SR channels causes a 90° phase shift of the water transport in these two regions. An example is shown in Figure 13 for the water transport across transects T1 and T2 around the spring tidal period. The water transport in the MHB-SR channel leads the water transport in the MHB-NB channel by 90°, even though its transport volume is about 3-7 times smaller. ...
Context 3
... result is the same as our model computation, indicating that FVCOM resolves the realistic water transport process in the MHB-NB system. Kincaid reported that the water transport estimated from the ADCP measurements was 7.5 Â 10 3 Figure 13. The time series of the tidal-driven water transport through transects T1 (thin solid line) and T2 (heavy solid line) around the spring tide in April 2001. ...
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... Numerical simulations were conducted using the 3-D hydrodynamic Finite Volume Coastal Ocean Model (FVCOM, version 4.1). The model is based on the free surface, 3-D primitive equations, finite-volume fluxes with unstructured-grid [Chen et al., 2003;Kobayashi et al., 1999], making it ideal for fine resolution coastal estuarine applications [Zhao et al., 2006]. The model domain covers Tracadie Bay and a portion of GSL connecting it, with a minimum horizontal resolution of 3 m near the shallow areas of the coast and a maximum of 480 m at the open boundary with a total of 42556 nodes and 77005 elements. ...
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... Unfortunately, the cross-scale models are not readily available for lagoonal estuaries. Most estuarine circulation models are truncated outside the bay with a focus only on tidal propagation and river plumes (Zhao et al., 2006). These models may neglect or underestimate the coastal currents that depend on broader coastal-shelf physics (Marchesiello et al., 2001). ...
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... The complicated topography and coastlines in the harbour require a high-resolution model that is able to describe flow structures with small spatial scales in the harbour (Larson et al. 2003;Li and Hondgins 2004). Moreover, a model with enough resolution to represent the abrupt changes in the geometry and topography is necessary because the small-scale variations of the coastline and topography are known to lead to submesoscale motions characterized with spatial scales of 100 m -10 km (Hannah and Wright 1995;Zhao et al. 2006;Lynge et al. 2010;Poje et al. 2010;Xu and Xue 2011;Poje et al. 2014;McWilliams 2016). However, high-resolution models, with a spatial resolution to fit the spatial scales in the harbour, are still not available, though the computational power has been significantly increased in recent years. ...
In the present paper, tides in the port of Vancouver Harbour have been investigated with a high-resolution three-dimensional hydrodynamic model based on FVCOM (Finite Volume Community Ocean Model). The model was evaluated against field observations including tidal elevations and tidal currents, and the evaluation showed that the model was in good agreement with the observational data. Using the model, we first investigated the horizontal distributions of tides, tidal currents, and tidally induced residual circulation, and then investigated the tidal asymmetry and dynamic mechanisms of tidal flows in the harbour. The tidal residual circulation shows a strong spatial pattern, which is associated with the local coastlines and variation of topography. The tidal asymmetry in the harbour is caused by different mechanisms, not only including the traditional factors, such as residual flows, the interaction between M2 and its overtide M4, but also the interaction of principal astronomical tides of O1, K1, and M2. The momentum balance is dominated by terms of the advection and the pressure gradient in First Narrows and Second Narrows, whereas terms of the local acceleration and the Coriolis are also important in the central harbour. The spatial variations of the momentum terms are strongly associated with the local changes in coastline and topography.
... A narrow channel connecting a bar-built bay to the coastal ocean can cause the generation of a complex set of tidal eddies over a tidal cycle that affect the net transport through the channel (Whilden et al., 2014). These tidal eddies have spatial scales similar to the channel width and can be difficult to correctly capture in a computational model (Zhao et al., 2006). Herein, we examine the effects of grid resolution on the representation of tidal eddies and modeled Lagrangian transport for the Galveston Bay ship channel in Texas, USA. ...
... Hydrodynamic models have been used to simulate the development of such eddies in the complex geometries of estuaries (e.g. Zhao et al., 2006;Yang and Wang, 2013). ...
In operational oil spill modeling, hydrodynamic models often employ a coarse-resolution grid for computational efficiency. However, this practical grid resolution poorly resolves small-scale flow features, such as starting jet vortices (tidal eddies) that are common at the inlet of bar-built estuaries with narrow inlet channels, particularly where channel dredging and jetties have been employed to aid ship traffic. These eddies influence Lagrangian transport paths and hence the fate of an oil spill potentially entering or leaving an estuary. This research quantifies the effect of tidal eddies on the mixing process and effects at model scales relevant to the operational prediction of oil spills, using the Galveston Bay entrance channel as a study site. Model grid sensitivity was analyzed, yielding an adequate eddy solution at the horizontal grid size of ∼140 m. It is demonstrated that the SUNTANS model at a practical operational grid resolution (∼400 m) captures neither the eddies nor their effects on particle movement, despite showing a satisfactory prediction of net transport through the inlet. The need for subgrid eddy modeling is discussed, and an empirical approach is proposed that can improve oil spill predictions at operational grid resolution scales when results from a high-resolution model are available.
... The Smagorinsky formulation [23] is used for horizontal mixing. FVCOM was successfully applied to studies of the deep ocean [24], the continental shelf [25], and estuaries [26,27]. In addition to encompassing the combined NGOFS, NWGOFS, and NEGOFS domains, the INGOFS domain also covers the Lower Mississippi River course, Lake Pontchartrain, Barataria Bay, the lower Atchafalaya River, Texas coastal inlets, and a portion of the Mexican coastal waters (Figures 1 and 2). ...
NOAA’s National Ocean Service is upgrading three existing northern Gulf of Mexico (GOM) operational nowcast/forecast systems (OFS) by integrating them into one single system (INGOFS) and developing additional domain coverage to encompass the lower Mississippi River, Lake Pontchartrain, Texas coastal embayments, and Mexican coastal waters. The system will produce real-time nowcast and short-range forecast guidance for water levels, 3-dimensional currents, water temperature, and salinity. INGOFS will be implemented using the Finite Volume Community Ocean Model (FVCOM). This paper describes the model configuration and results from a one-year (2 August 2016–1 August 2017) hindcast simulation. The model grid is composed of about 300,000 nodes and 600,000 elements, and has a spatial resolution ranging from 45 m near the coast to around 10 km on the open ocean boundary. It uses the FVCOM wetting and drying feature, the quadratic bottom friction scheme, and the two-equation model of the Mellor-Yamada Level 2.5 turbulence closure scheme. The hindcast results of water levels, surface temperatures, and salinity were verified by comparing the model time series with in situ observations. The root-mean-squared errors are about 0.08 m for water levels, about 1.1 °C for temperatures, and about 3.7 psu for salinity. The hindcast configuration will be further tested in a nowcast/forecast environment for a one-year period. The upgraded system is anticipated to be in operational production in mid-2020.
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... Model selection criteria and evaluation, where 3D 3D hydrodynamics, WD wetting and drying, WQ water quality/transport module, OP open-source code, PP pre-/post-process, DT documentation and technical support However, as previously illustrated this technique is highly inaccurate and computationally costly if there is interest in a particular area. To overcome this disadvantage under his supervision, quadtree grid technique was introduced in [41]. This technique was applied to simulate the water circulation of a large shallow lake, Lake Balaton, Hungary. ...
This chapter presents a review of previous studies related to the numerical modelling of the hydrodynamics of coastal lakes with emphasis on Egyptian coastal lakes. Also, related applications, such as water quality management and sediment transport scenarios in lakes, are presented. The focus is primarily on existing, well-established, numerical models and their applications to shallow water systems. The chapter starts with a general introduction to lake modelling followed by the techniques and assumptions that are commonly used. A summary of the available hydrodynamic models categorised based on whether they are one-, two-, or three-dimensional is presented. Previous hydrodynamic modelling of lakes is reviewed under a separate section within this chapter as well as those studies related to water quality management.
... The hydrodynamic and transport model used for this study is the 3-D unstructured-grid Finite-Volume Coastal Ocean Model (FVCOM) developed by Chen et al. (2003). FVCOM has been extensively used by the estuarine and coastal modeling community to study a variety of scientific and engineering problems (Zhao et al., 2006;Chen et al., 2008;Sun et al., 2013;Yang et al., 2015). The model simulates hydrodynamics and scalar transport in an integral form by computing fluxes between non-overlapping horizontal triangular control volumes. ...
... The model computes water depths, velocities, salinities, and water-surface elevations based on the geometry and bathymetry of the system, the specified lateral and vertical boundary conditions, and model input parameters. FVCOM has been extensively applied to simulate hydrodynamics and transport processes in many coastal regions and estuaries around the world, including several estuaries and bays in Puget Sound (Zhao et al. 2006;Rego and Li, 2010;Yang et al., 2010Yang et al., , 2012Dukhovskoy and Morey, 2011;Chen et al. 2012;Yang and Wang, 2013). ...
... With an accurate geometric representation of irregular coastlines and islands and sufficiently high horizontal resolution in narrow channels, FVCOM provides an accurate simulation of the tidal current in the bays and also resolves the strong tidal flushing processes in the narrow channels. More detailed description can be seen in Zhao et al. (2006). 2002), we use the objective criterion of the Okubo-Weiss parameter to identify eddies from SLA maps. ...
... It can be seen from the distributions of the near-surface tidal current that there exist multiple eddies due to the interaction of tidal flushing and complex coastlines both in Jiaozhou Bay (Fig. 2) and Aoshan Bay (Fig. 3). The formation of these eddies is mainly due to the current separation either at the tip of the coastlines or asymmetric tidal flushing in narrow channels or passages according to Zhao et al. (2006). Based on different period, we separate these eddies into two types: eddy shedding from the tidal flushing, and steady eddies identified from the residual flow field. ...
Design of the in-situ observational sites depends on topography and hydrodynamic characteristics in the observational region, which is significantly important in marine environmental monitoring and evaluation. The tidal motion in Jiaozhou Bay and Aoshan Bay is simulated in this study using the unstructured grid, finite-volume coastal ocean model (FVCOM). With an accurate geometric representation of irregular coastlines and islands and sufficiently high horizontal resolution in narrow channels, FVCOM provides an accurate simulation of the tidal current in the bays and also resolves the strong tidal flushing processes in the narrow channels. There exist many small-scale eddies due to the interaction of tidal flushing and complex coastlines. Small-scale eddies formation will cause inhomogeneous distribution of the marine environmental element, then affects design of the in-situ observational sites. We proposed that design of the in-situ observational sites should consider nearshore eddies in order to conform to reality and enhance environmental protection.
