A high resolution hydrodynamic model for the greater Port Hawkesbury area

Transcription

1 A high resolution hydrodynamic model for the greater Port Hawkesbury area Adam Drozdowski 1, Donghui Jiang 1, Edward Horne 1, Fred Page 2, David Greenburg 1 1 Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, NS, B2Y 4A2, Canada. 2 St. Andrews Biological Station, St. Andrews, NB, E5B 2L9, Canada A high resolution regional model for Port Hawkesbury Nova Scotia is being developed in support of the World Class Tanker Safety project with the goal of providing real time hydrographic products relevant to navigation and operational response near Port Hawkesbury and approaches. The modelling work utilizes an unstructured mesh and is based on the Finite Volume Community Ocean Model (FVCOM). Horizontal resolution varies from 10 s of meters in narrows channels and small bays to hundreds of meters on the shelf. The model is forced with winds and tides. Validations indicate good agreement with observed vertically averaged tidal currents and elevation but mixed results for in-situ currents. The effectiveness of further developments, such as enlarging the model domain and including high resolution HRDPS winds, are explored.

2 Comparison of open boundary condition options for modeling at Shinnecock Bay, Long Island, New York Jeong Eun Ahn 1, Anne Dudek Ronan 1 1 Civil and Urban Engineering, NYU Tandon School of Engineering, NY, USA Open boundary conditions of hydrodynamic models are often specified using global tide models. Although these models agree within 2 to 3 cm in the deep ocean, there are larger differences in shallow waters (Shum et al. 1997). The aims of this study are to (1) compare two ocean tide models (LeProvost and TPXO) and (2) evaluate the differences between two hydrodynamic models (ADCIRC and FVCOM). Each model was forced at the open boundary with five major tidal constituents (M2, N2, S2, O1, K1) in different ways. The study area is Shinnecock Bay on the south shore of Long Island, New York, which is connected to the Atlantic Ocean. This study used the mesh that was developed by the U.S. Army Corps of Engineers (Militello and Kraus, 2001) and distributed at the ADCIRC website ( tidalforcing-example/). The tidal forcing at the open boundary was generated using LeProvost and TPXO. The extracted amplitudes and phases of the tidal constituents were compared at the open boundary, which were located in shallow waters. The maximum standard deviation of amplitudes is consistent with prior work of deep waters even though it is in shallow waters. Model surface elevations predicted by both ADCIRC and FVCOM were compared to NOAApredicted water surface elevation at a tidal station in the model domain. The results were sensitive to the choice of global tide model as well as physical mixing, bottom friction coefficients, and discretization algorithm. FVCOM also was forced at the open boundary by elevation time series and this option produced the best match to the NOAA prediction for this case, which is focusing on tidal circulation rather than other physical processes. References Militello, A. and N.C. Kraus Shinnecock Inlet, New York, Site Investigation Report 4, Evaluation of Flood and Ebb Shoal Sediment Source Alternatives for the West of Shinnecock Interim Project, New York. Coastal Inlets Research Program, Tech. Rpt. CHL-98-32, U.S. Army Engineer Research and Development Center, Vicksburg, MS. Shum, C.K., P.L. Woodworth, O.B. Andersen, G.D. Egbert, O. Francis, C. King, S.M, Klosko, C. Le Provost, X. Li, J-M. Molines, M.E. Parke, R.D. Ray, M.G. Schlax, D.Stammer, C.C. Temey, P. Vincent, and C.I. Wunsch Accuracy assessment of recent ocean tide models. J Geophys Res 102(C11):

3 Tidal propagation in Fraser River Estuary Yongsheng Wu 1, Mitchell O'Flaherty-Sproul 1, Charles Hannah 2, Xiaoyi Wang, Zeliang Wang, de Lange Boom Bodo 3 1 Marine Ecosystem Section, Ocean and Ecosystem Sciences Division, Fisheries and Oceans Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, B2Y 4A2, Canada 2 Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, V8L 4B2, Canada. 3. Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, V8L 4B2, Canada. CHS Information of tidal propagation in estuaries is of scientific and engineering importance for tidal prediction, offshore engineering design, marine navigation, sediment transport, and estuarine ecosystem. In the present study, propagation of tides in the Fraser River has been investigated with a 3-D hydrodynamics model based on FVCOM, which covers from the estuary to about 100 km upstream of the river with a horizontal resolution as high as 10 m. The model was validated with observational data including the water elevations and currents, and good agreement was obtained. Our results indicate that principal tides attenuate from the estuary to upstream along the river with increasing river discharges. However, over tides and compound tides amplified along the river first and then decreases, the turning location is associated with the relative balance between the nonlinear effect and the attenuation of principal tides. Using model results, change mechanisms of tides are analyzed.

4 On the Momentum Balance of Tampa Bay Jing Chen 1, Robert H. Weisberg 1, Lianyuan Zheng 2, Yonggang Liu 1 1 College of Marine Science, University of South Florida, St. Petersburg, FL 2 NOAA-NOS, Silver Spring, MD In its simplest sense, the momentum balance for the non-tidal, density driven circulation of a partially mixed estuary is generally considered to be between the pressure gradient force and vertical friction, the result being a two layered mean circulation. However, all estuaries tend to have geometric complexities that may alter this simplistic view. Here we apply the FVCOM to diagnose the momentum balance distribution for Tampa Bay, a partially mixed estuary on Florida s west coast. This is the fourth in a series of analyses, the three previous ones being on the circulation, the flushing times and the salt balance. With resolution as fine as 20m, the model resolves the channels, inlets, bridge causeways and other geometric complexities. Detailed comparisons between the model simulated circulation and observations over time scales associated with the tidal, wind and density driven modes of circulation provide justification for the other analyses. Point by point, three-dimensional momentum equation balances demonstrate that while the general expectation for non-tidal estuarine flow is met, the actual distributions of terms in the momentum equation are quite complex when real geometries are considered.

5 Evaluating the linkage between circulation and spatial water quality patterns in the nearshore of South-eastern Georgian Bay Lakshika Girihagama 1, Mathew Wells 1, Jingzhi Li 1, and Todd Howell 2 1 Dept. of Physical & Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada. 2 Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Toronto, ON M9P 3V6, Canada. Flushing mechanisms - driven by the natural circulation - play a dominant role in understanding the impact of land-based phosphorus on the nearshore water quality of South-eastern Georgian Bay, Ontario. Georgian Bay is located east of the main body of Lake Huron and has a surface area of 15,000 km², and contains approximately 30,000 islands. Generally the water quality is very good, but there are concerns about the impact of ongoing development upon the many inlets and bays along the eastern shore. Detailed observations of nearshore water quality (e.g. conductivity, phosphorous, chlorophyll) from Shwanaga and Moon River Island regions show pronounced gradients, presumably driven by water circulation patterns. This region experiences seasonal thermal stratification, and observations from the current moorings show a pronounced barotropic variability in currents that is tied to variability in surface water levels. The water level measurements from Shwanaga Islands level loggers show a dominant period of 12.4 h, corresponding to the dominant surface seiche mode of Georgian Bay. The numerous islands on the topographically complex eastern shore of Georgian Bay make it a challenging setting to understand water circulation patterns. In order to obtain a better understanding of the flushing dynamics and the resulting phosphorus-productivity gradient across the South-eastern Georgian Bay, a circulation model will be developed using FVCOM (Finite Volume Coastal Ocean Model) to help interpret and synthesize the field data.

6 West Florida Shelf Upwelling: Origins and Pathways Robert H. Weisberg 1, Lianyuan Zheng 2, Yonggang Liu 1 1 College of Marine Science, University of South Florida, St. Petersburg, FL 2 NOAA-NOS, Silver Spring, MD Often described as oligotrophic, the west Florida continental shelf supports abundant fisheries, experiences blooms of the harmful algae, Karenia brevis and exhibits subsurface chlorophyll maxima evident in shipboard and glider surveys. Renewal of inorganic nutrients by the upwelling of deeper ocean water onto the shelf may account for this, but what are the origins and pathways by which such new water may broach the shelf break and advance toward the shoreline? We address these questions via numerical model simulations of water parcel trajectories using the West Florida Coastal Ocean Model (WFCOM) that downscales from the deep ocean, across the continental shelf and into the estuaries by nesting FVCOM in HYCOM. Novel to our approach is the calculation of trajectories that are kinematical consistent with local isopycnic surfaces. Focus is on 2010, when the west Florida shelf was subjected to an anomalously protracted period of upwelling caused by Gulf of Mexico Loop Current interactions with the shelf slope. Origins and pathways are determined by integrating trajectories over successive 45 day intervals, beginning from different locations along the shelf break and at various locations and depths along the shelf slope. Waters upwelling across the shelf break are found to originate from relatively shallow depths along the shelf slope. Even for the anomalous 2010 year, much of this upwelling occurs from about 150 m and above, although waters may broach the shelf break from 300 m depth, particularly in the Florida Panhandle. Such interannual renewal of west Florida shelf waters appears to have profound effects on west Florida shelf ecology.

7 VALIDATING FVCOM 30 YEAR HINDCAST WITH SURFACE DRIFTER AND BOTTOM TEMPERATURE AND VELOCITY DATA FOR APPLICATION TO FISH RECRUITMENT AND STOCK MANAGEMENT IN GULF OF MAINE Vitalii A. Sheremet 1, James P. Manning 1 1 NOAA, Northeast Fisheries Science Center, 166 Water Street, Woods Hole, MA We developed programming tools in Python language for accessing FVCOM model data, performing cubic Bezier-Bernstein triangular grid interpolation, drifter tracking, and larvae retention analysis. We created particle trajectory dataset for weekly launches over Georges Bank area for years pertinent for fisheries recruitment analysis. FVCOM simulation results were validated by comparing with temperature and velocity records derived from lobster traps deployed as a part of the Environmental Monitors on Lobster Trap (emolt) program and by comparing with surface drifter deployments. It was found that the FVCOM model is a useful tool for fisheries egg and larvae transport analysis in the upper ocean. Near bottom FVCOM shows somewhat warmer temperatures and less realistic currents compared to observations. It was found that using the depth averaged currents of FVCOM predicts reasonable dispersion characteristics of fish egg and larvae at early stages of evolution, with interannual variability amplitudes similar to the observed ones. However, direct correlations between particle retention index and recruitment survey data for each year were not found. This suggests that the larvae transport is just one mechanism among many affecting the recruitment.

8 Update and Improvements of FVCOM: A release of FVCOM version 4.0 Changsheng Chen 1, Robert C. Beardsley 2 and Jinhua Qi 1 1 School for Marine Science and Technology, University of Massachusetts-Dartmouth, New Bedford, MA Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA Our team of University of Massachusetts-Dartmouth and Woods Hole Oceanographic Institution researchers has been continuing to develop and improve the prognostic, free-surface, threedimensional primitive equations-based unstructured-grid, Finite-Volume Community Ocean Model (FVCOM) since The updated version 4.0 of FVCOM has become a fully icecurrent-wave-sediment coupled model system with options for multi-domain nesting, two-way air-sea interactions and offline or online integration of ecosystem and water quality models. Several new modules are implemented, which include: cohesive sediments, ice embedding, and surface waves applicable for global application. As examples, a global-regional-coastalestuarine-wetland nested FVCOM model system was developed to resolve and examine multiscale oceanic responses to climate change. The unstructured grid used in the system provides accurate fitting of the complex coastal geometry and steep slope topography with spatial scales up to 2 km in the global ocean to 10 m over wetlands. This nested model system was validated by a 38-year hindcast simulation through comparisons with available observational data. It was served as a framework to establish the Northeast Coastal Ocean Forecast System (NECOFS). The NECOFS is an integrated atmosphere-ocean-wave model system in which the ocean model domain covers the northeast US coastal region with a horizontal resolution of km in the open ocean, 1-5 km on the shelf, and down to 20 m in estuaries, inner bays, inlets and harbors. The system produces 3-day forecast fields of surface weather, surface icing, waves, water level, temperature, salinity, currents and storm-induced coastal inundation; with daily updating using data assimilated fields whenever field data are available. It was validated for both hindcast simulation over and forecast operations for storm-induced inundation. Built on the same framework, we have also established an Arabian Gulf-Sea of Oman atmosphere-ocean forecast system (named AGSO-FVCOM). The AGSO-FVCOM is configured with a horizontal resolution varying from ~100 m to 10 km. This system runs through nesting with Global- FVCOM and has been placed into the 24/7 forecast operations since March 2015.

9 Reconstructing turbulent heat fluxes over Lake Erie during the extreme lake effect snow in November 2014 Ayumi Fujisaki-Manome 1, Lindsay Fitzpatrick 1, Andrew Gronewold 2, Eric Anderson 2, Chris Spence 3, Jiquan Chen 4, Changliang Shao 4 1 Cooperative Institute for Limnology and Environmental Research 2 Great Lakes Environmental Research Laboratory 3 Environment Climate Chance Canada 4 Michigan State University This study examined the evaporation from Lake Erie during the record lake effect snowfall event, November 17-20, 2014 by reconstructing heat fluxes and evaporation rates over Lake Erie using the unstructured grid, Finite-Volume Community Ocean Model (FVCOM). Nine different model runs were conducted using combinations of three different flux algorithms; the Met Flux Algorithm (COARE), a method routinely used at NOAA s Great Lakes Environmental Research Laboratory (SOLAR), and the Los Alamos Sea Ice Model (CICE); and three different meteorological forcings; the Climate Forecast System version 2 Operational Analysis (CFSv2), Interpolated observations (Interp), and the High Resolution Rapid Refresh (HRRR). A few non- FVCOM model outputs were also included in the evaporation analysis from atmospheric reanalyses (CFSv2 and NAM), the large lake thermodynamic model (LLTM). The simulated sensible and latent heat fluxes were validated with the eddy covariance measurements at two offshore sites; Long Point Lighthouse and Toledo Water Crib Intake. The evaluation showed a significant increase in heat fluxes over three days with the peak on the 18 th of November. Cumulative lakewide evaporation was comparable with the spatially integrated snow water equivalent data from the National Operational Hydrologic Remote Sensing Center, indicating that lake evaporation should account for the majority of snow precipitation. The ensemble runs presented a variation in spatial pattern of evaporation, lake-wide average evaporation, and resulting cooling of the lake. The variation among the nine FVCOM runs resulted in the variation of 3D mean temperature cooling by 3-5 C O (6-10 EJ loss in heat content), implication for impacts on preconditioning for the upcoming ice season.

10 Simulating hydrodynamics and ice cover in Lake Erie using an unstructured grid model Ayumi Fujisaki-Manome, Jia Wang 2, and Eric Anderson 2 1 University of Michigan 2 NOAA Great Lakes Environmental Research Laboratory An unstructured grid Finite-Volume Community Ocean Model (FVCOM) is applied to Lake Erie to simulate seasonal ice cover. The model is coupled with an unstructured-grid, finite-volume version of the Los Alamos Sea Ice Model. This model, FVCOM-Ice hereafter, is applied to a shallow freshwater lake for the first time with a comprehensive parameter study of the ice dynamic model. Multi-year simulations results from 2003 to 2014 were compared with the observed ice extent, water surface temperature, ice thickness, and water temperature profiles, as well as with model results from an existing Princeton Ocean Model coupled with an ice model (ICEPOM). Clear improvement in simulating slow decay of ice extent in spring was achieved by FVCOM-Ice from the previous results with ICEPOM. FVCOM-Ice successfully reproduced the deformed ice spectrum in the probability density distribution of ice thickness observed in the insitu measurements. Interestingly, the classical Hibler s formula for the ice strength parameterization resulted in better agreement with the observed probability density distribution of ice thickness than the relatively new energy-based ice strength. The latter tended to underestimate in the deformed ice spectrum and to overestimate ice thickness. The winter thermal structure observed in the thermistor measurements in 2005 was reasonably reproduced by FVCOM-Ice with some improvement from the previous ICEPOM results, which was likely from the updated overland/overlake method to create meteorological forcing.

11 Simulating Oceanic Responses of Placentia Bay to Hurricane Leslie Zhimin Ma 1,2, Guoqi Han 1 and Brad de Young 2 1 Biological and Physical Oceanography Section, Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John s, Newfoundland, Canada 2 Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John s, Newfoundland, Canada We use a three-dimensional, baroclinic finite-volume ocean model (FVCOM) to examine oceanic responses of Placentia Bay to Hurricane Leslie in September Hurricane Leslie made landfall at the south coast of Newfoundland on September 11, The FVCOM model is forced by reconstructed winds during the storm period. The modelled storm surge magnitude and timing agree well with tide-gauge observations. The sea surface cooling in the outer Bay is well reproduced by the model. The model results show strong near-inertial oscillation, consistent with observations.

12 Simulation of upper ocean currents and waves in hurricanes using FVCOM-SWAVE Yujuan Sun 1, Will Perrie 1 1 Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, NS, B2Y 4A2, Canada. The capability of FVCOM-SWAVE to simulate the upper ocean currents and waves generated by high-wind speeds in hurricanes is investigated in our study. Effect of wave-current interaction on wave is discussed through the simulation of the process of Hurricane Bill (2009). Furthermore, based on the best track of Hurricane Bill (2009), we generated the idealized wind fields using the Holland symmetric method. The symmetric wind fields are applied in the model to simulate the wave conditions under different translation speeds, intensities of hurricanes. The effect of drag coefficients for wind stress on wave simulation is also discussed in this study.

13 Impact of Sea Level Rise on Future Storm-induced Coastal Inundation Robert C. Beardsley 1 and Changsheng Chen 2 1 Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA School for Marine Science and Technology, University of Massachusetts-Dartmouth, New Bedford, MA As supported by the NERACOOS Program, the team of University of Massachusetts-Dartmouth and Woods Hole Oceanographic Institution researchers has established the Northeast Coastal Ocean Forecast System (NECOFS). NECOFS is an integrated atmosphere-ocean model system in which the ocean model domain covers the northeast US coastal region (the New England Shelf, Georges Bank, the Gulf of Maine, and the Scotian Shelf) with a horizontal resolution of km in the open ocean, 1-5 km on the shelf, and down to 10 m in estuaries, inner bays, inlets and harbors. NECOFS also includes fully coupled current-wave coastal inundation model systems for Scituate ( MA), Mass Bay/Boston Harbor (MA), Hampton River (NH), and Saco Bay (ME). Using this system, we have examined the impact of sea level rise on future storminduced coastal inundation in Scituate and Mass Bay/Boston Harbor. Experiments were made for a selected hundred-year nor easter storm (February 1978 storm) and 10-year storm (August 1991 Hurricane Bob). Our experiments show that as a result of the mean sea level rise, for a given same storm as before, the surface wave height could be significantly increased and thus the surge level. We will face a greater threat from wave runup inundation during hurricanes and nor easter storms in the future.

14 Opportunities and Challenges in NOS Operational Forecast Systems NOAA/NOS/CO-OPS/OD Modeling Team 1, presented by Lianyuan Zheng 1 NOAA-NOS, Silver Spring, MD NOAA s National Ocean Service (NOS) has been developing and maintaining a national network of hydrodynamic operational oceanographic nowcast and forecast modeling systems to support navigational and environmental applications in U.S. coastal and estuarine waters, and the Great Lakes. These operational forecast systems (OFS) provide the maritime community with nowcast and forecast guidance of water levels, currents, water temperature, and salinity for 48 to 120 hours. NOS has collaborated with NOAA s National Weather Service (NWS) and Office of Oceanic and Atmospheric Research (OAR) and extramural partners from academia and the local maritime community to develop and implement the current suite of NOS OFS. NOS currently operates and maintains 15 OFS for the U.S. East and West coasts, the Gulf of Mexico, and the Great Lakes, to cover approximately 35% of the CONUS coast. Over the next 8 to 10 years, NOS intends to provide complete coverage of the continental U.S and establish the necessary national infrastructure to enable other types of forecasts. This presentation will provide an overview of FVCOM-based NOS OFS, their performance, and present challenges that the program is facing. We are exploring opportunities to collaborate with the community of FVCOM users to address these challenges and leverage advances in FVCOM development and applications to improve our OFS suite.

15 Storm surge estimation around Japan using Finite Volume Community Ocean Model and Meso-scale model data Takahiro Kayahara 1,Satoshi Iizuka 1, Koji Kawasaki 2, Masaki Nimura 2, Shinya Simokawa 1, and Jun Sasaki 3 1 National Research Institute for Earth Science and Disaster Resilience 2 Hydro-soft Technology Institute 3 University of Tokyo Typhoons often hit Japan, sometimes leading to inundation damage due to storm surge. In order to evaluate the possible risk caused by storm surge in Japan, we have implemented a Finite Volume Community Ocean Model (FVCOM). The model was forced by Meso-Scale Model (MSM) Grid Point Value (GPV) data of Japan Meteorological Agency and the Ocean Tidal Model NAO.99Jb, and then the results are validated for Typhoon Jelawat in 2012 and Typhoon Phanfone in These typhoons caused the relatively large tide level deviation in Tokyo Bay in recent years. The model is successful in simulating the peak time of highest level for both Typhoon cases, although the amplitude is somewhat underestimated compared to observations. In addition, the impact of difference in landfall times of typhoon will be discussed.

16 Tools for Tidal Analysis in the Bay of Fundy Jeremy Locke 1, Dr. Richard Karsten 1 1 Acadia University, Wolfville, Nova Scotia, Canada The age of nonrenewable dirty energy is coming to an end. Tidal power has global potential to help to begin the new age. The site of the largest tides on Earth, Canada s own Bay of Fundy, has an assessed capacity to supply in excess of 2 GW more than three times the power output of Nova Scotia s largest coal plant and roughly 80% of the province s present maximum output. Accurate insights on tidal phenomena are of utmost importance for Nova Scotia s emerging tidal industry to become a feasible energy source to supply the province. In order to make accurate site assessments, Acadia University has developed expertise is in the realm of numerically simulating tides in the Bay of Fundy using the Finite-Volume Community Ocean Model (FVCOM). In a new project starting Fall 2016, Acadia numerical data will be used to help study turbulent behavior at hub height. The Vectron an instrument that combines several acoustic Dopplers to measure turbulence will be deployed at four sites in the Minas Passage for twomonth intervals throughout to collect tidal data for the project. The Vectron s data will be used twofold to study turbulence properties and to validate FVCOM outputs that have been post-processed by the python package PySeidon. The ability to predict tidal behavior and select optimal turbine deployment sites will increase turbine mechanical lifetime and reduce the industry s investment risk. Data from this project will directly benefit both the local tidal industry with precision measurements of the Minas Passage area and the global tidal industry with research on tidal behavior.