Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Locations of convergences in the maximum alongshore current

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Frequently anticipated questions:


What does this data set describe?

Title:
Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Locations of convergences in the maximum alongshore current
Abstract:
The U.S. Geological Survey has developed a method for estimating the mobility and potential alongshore transport of heavier-than-water sand and oil agglomerates (tarballs or surface residual balls, SRBs). During the Deepwater Horizon spill, some oil that reached the surf zone of the northern Gulf of Mexico mixed with suspended sediment and sank to form sub-tidal mats. If not removed, these mats can break apart to form SRBs and subsequently re-oil the beach. A method was developed for estimating SRB mobilization and alongshore movement. A representative suite of wave conditions was identified from buoy data for April, 2010, until August, 2012, and used to drive a numerical model of the spatially-variant alongshore currents. Potential mobilization of SRBs was estimated by comparing combined wave- and current-induced shear stress from the model to critical stress values for several sized SRBs. Potential alongshore flux of SRBs was also estimated to identify regions more or less likely to have SRBs deposited under each scenario. This methodology was developed to explain SRB movement and redistribution in the alongshore, interpret observed re-oiling events, and thus inform re-oiling mitigation efforts.
Supplemental_Information:
This data layer is a subset of USGS Open-File Report 2012-1234, Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance. It is part of a set of data layers describing convergences in the maximum (in terms of absolute value) alongshore current for a range of wave climate scenarios. The specific wave conditions and object parameters for this layer are indicated by the file name (of format Hh_Dd_conv), and in the shapefile attributes, and may be found by comparing the scenario name (Hh_Dd) to the look-up table included in the GIS zip file, wave_scenarios.txt. NOTE: Scenarios H3_D6, H4_D5, H4_D12, H4_D13, H5_D4, H5_D5, and H5_D12 do not have convergences, and no GIS files exist in for these cases.
  1. How might this data set be cited?
    Dalyander, P. Soupy, Long, Joseph W., Plant, Nathaniel G., and Thompson, David M., 2012, Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Locations of convergences in the maximum alongshore current: U.S. Geological Survey Open-File Report 2012-1234, U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

    This is part of the following larger work.

    Plant, Nathaniel G., Long, Joseph W., Dalyander, P.Soupy, and Thompson, David M., 2012, Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: U.S. Geological Survey Open-File Report 2012-1234, U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.504638
    East_Bounding_Coordinate: -85.560731
    North_Bounding_Coordinate: 30.390730
    South_Bounding_Coordinate: 30.017758
  3. What does it look like?
    model_bathymetry.jpg (JPEG)
    Graphic showing the numerical model domain over which analysis is conducted.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 01-Apr-2010
    Ending_Date: 01-Aug-2012
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference: Gulf of Mexico
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (6)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 0.01 m
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Hh_Dd_conv
    Locations of convergences in the maximum alongshore current for specific wave scenarios (Source: USGS)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: ESRI) Coordinates defining the features.
    Scenario_H
    Scenario wave height number (e.g., "h" in Hh_Dd, see wave_scenarios.txt) (Source: USGS)
    Range of values
    Minimum:1
    Maximum:5
    Units:non-dimensional
    Resolution:1
    Scenario_D
    Scenario wave direction number (e.g., "d" in Hh_Dd, see wave_scenarios.txt) (Source: USGS)
    Range of values
    Minimum:1
    Maximum:16
    Units:non-dimensional
    Resolution:1
    converge
    All of the latitude and longitude points in this layer are convergences, indicated by a value of one in this attribute. (Source: USGS)
    Range of values
    Minimum:1
    Maximum:1
    Units:non-dimensional
    Resolution:1

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • P. Soupy Dalyander
    • Joseph W. Long
    • Nathaniel G. Plant
    • David M. Thompson
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    P. Soupy Dalyander
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2290 (voice)
    (508) 457-2310 (FAX)
    sdalyander@usgs.gov

Why was the data set created?

This GIS layer contains an estimate of the locations of convergences in the maximum (in terms of absolute value) alongshore current in the shallow northern Gulf of Mexico (Alabama and portion of the Florida coast) for a single set of wave conditions. Convergences are locations where the flow from both east and west is directed toward the point, e.g., positive (eastward) flow to the west and negative (westward) flow to the east. This output is based on numerical model output of wave and circulation patterns for a given wave height scenario, corresponding to a particular set of offshore wave conditions at NOAA NDBC buoy 42040. The specific wave conditions for a given layer are indicated by the file name (of format Hh_Dd_conv), also found in the shapefile attributes, and may be found by comparing the scenario name (Hh_Dd) to the look-up table included in the GIS zip file, wave_scenarios.txt. This data layer is intended to show patterns in alongshore current for intended use by individuals in SRB mitigation attempting to explain redistribution of SRBs under specific wave conditions.

How was the data set created?

  1. From what previous works were the data drawn?
    NOAA GFS (source 1 of 2)
    NOAA National Centers for Environmental Prediction (NCEP), 20110601, NOAA/NCEP Global Forecast System (GFS) Atmospheric Model: NOAA National Centers for Environmental Prediction, Camp Springs, MD.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    Wind speed data at 10 m above the sea surface from the NOAA Global Forecast System (GFS) 0.5 degree model is interpolated by NOAA to the 4' Wavewatch3 grid and archived. These archived data are used to drive the numerical wave and circulation model that creates estimated of bottom shear stress.
    NOAA WW3 (source 2 of 2)
    NOAA National Centers for Environmental Prediction (NCEP, 20121001, NOAA/NWS/NCEP 4' Wavewatch III Operational Wave Forecast: NOAA National Centers for Environmental Prediction, Camp Springs, MD.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    Boundary conditions for the wave model were provided by the 4' NOAA/NWS/NCEP Wavewatch III operational ocean wave forecast.
  2. How were the data generated, processed, and modified?
    Date: 2012 (process 1 of 7)
    The D-Flow and D-Waves components of the Deltares Delft3D numerical model suite (version 4.00.01) were used to estimate east and north components of wind and wave-driven velocity for the offshore wave conditions corresponding this scenario Hh_Dd (characteristics of which may be found in the included wave_scenarios.txt file) in each grid cell in the model domain. The wave model D-Waves, based on the Simulating WAves Nearshore (SWAN) model, is a 3rd generation phase-averaged numerical wave model which conserves wave energy subject to generation, dissipation, and transformation processes and resolves spectral energy density over a range of user-specified frequencies and directions. D-Wave was used in stationary mode. D-Flow solves the shallow water Navier Stokes equations and is run in 2-D depth-averaged mode, with linkage to D-Waves allowing the generation of wave-driven currents via wave radiation stress forcing. Default values for model parameters governing horizontal viscosity, bottom roughness, and wind drag were used. Neumann boundary conditions were used along the east, west, and south model boundaries with harmonic forcing set to zero. Model bathymetry was provided by the NOAA National Geophysical Data Center Northern Gulf Coast digital elevation map, referenced to NAVD88.
    Significant wave height, dominant wave period, and wave direction were prescribed as D-Wave TPAR format files every 30 grid cells along the model boundary using results from the NOAA Wavewatch III 4' multi-grid model for a representative moment in time corresponding to the offshore wave conditions of the scenario, the specific time of which may be found in the included wave_scenarios.txt file. A JONSWAP (JOint NOrth Sea WAve Project) spectral shape was assumed at these boundary points. Wind forcing was provided using the archived WavewatchIII 4' winds, extracted from the NOAA GFS wind model, for this time. The D-Wave directional space covers a full circle with a resolution was 5 degrees (72 bins). The frequency range was specified as 0.05-1 Hz with logarithmic spacing. Bottom friction calculations used the JONSWAP formulation with a uniform roughness coefficient of 0.067 m2/s3. 3rd-generation physics are activated which accounts for wind wave generation, triad wave interactions and whitecapping (via the Komen et al parameterization). Depth-induced wave breaking dissipation is included using the method of Battjes and Janssen with default values for alpha (1) and gamma (0.73). Current model outputs of east and north current velocity component were extracted and interpolated to the wave model grid (staggered points in relation to the current model grid).
    NDBC observations from station 42012 for the representative scenario time periods were used to validate the wave model results. Person who carried out this activity:
    Joseph W. Long
    U.S. Geological Survey
    Oceanographer
    600 4th Street S
    St. Petersburg, FL
    USA

    (727) 803-8747 x3024 (voice)
    (727) 803-2032 (FAX)
    jwlong@usgs.gov
    Data sources used in this process:
    • NOAA GFS
    • NOAA WW3
    Data sources produced in this process:
    • DELFT3D
    Date: 2012 (process 2 of 7)
    Identify the spatial extent of the surf zone at each alongshore location using Mathworks MATLAB software (v2012A). The shoreline is identified from the gridded bathymetry as the cross-shore grid cell of minimum water depth at each alongshore transect. In areas where lagoons separate barrier islands and the mainland coast, the shoreline is considered along the seaward side of the barrier island only. The shoreline is not continuous due to interruptions at inlets.
    For each alongshore transect, the surf zone is defined as the area between the shoreline and the location of maximum wave height (found in a search area extending from the shoreline to the most offshore point of modeled depth-induced wave breaking dissipation). The extent of the surf zone (as indices into the grid at each alongshore location of the cross-shore position of the shoreline and seaward edge of the surf zone) was saved for all of the scenarios into a MATLAB .mat structure. Person who carried out this activity:
    David Thompson
    U.S. Geological Survey
    Oceanographer
    600 4th Street S
    St. Petersburg, FL
    USA

    (727) 803-8747 x3079 (voice)
    (727) 803-2032 (FAX)
    dthompson@usgs.gov
    Data sources used in this process:
    • DELFT3D
    Data sources produced in this process:
    • SURFZONE
    Date: 2012 (process 3 of 7)
    The maximum (in terms of magnitude) alongshore current within the surf zone at each alongshore location was computed in Mathworks MATLAB v2012A using modeled flow velocities. The alongshore variant maximum velocity vector was then smoothed with a 2-km Hanning window filter to remove small-scale variations likely caused by model noise. Person who carried out this activity:
    David Thompson
    U.S. Geological Survey
    Oceanographer
    600 4th Street S
    St. Petersburg, FL
    USA

    (727) 803-8747 x3079 (voice)
    (727) 803-2032 (FAX)
    dthompson@usgs.gov
    Data sources used in this process:
    • DELFT3D
    • SURFZONE
    Data sources produced in this process:
    • CURRENT
    Date: 2012 (process 4 of 7)
    For each scenario, locations of convergences in the maximum alongshore current are computed by finding adjacent grid cells where the current velocity transitions from eastward-directed (positive alongshore velocity) to westward-directed (negative alongshore velocity). The convergence is always selected as the negative velocity cell. Person who carried out this activity:
    Joseph W. Long
    U.S. Geological Survey
    Oceanographer
    600 4th Street S
    St. Petersburg, FL
    USA

    (727) 803-8747 x3024 (voice)
    (727) 803-2032 (FAX)
    jwlong@usgs.gov
    Data sources used in this process:
    • CURRENT
    Data sources produced in this process:
    • CONVERGE
    Date: 2012 (process 5 of 7)
    Export the values for each alongshore location from MATLAB format into an ArcGIS point shapefile using the Mathworks MATLAB Mapping Toolbox (v2012A). The latitude and longitude coordinates correspond to the identified shoreline location for each alongshore location. A single "converge" attribute is given a value of one; all latitute and longitude points in the file are convergence locations. The shapefile is written with the "shapewrite" command. Because MATLAB does not assign a projection, the projection corresponding to the projection associated with the bathymetry used in the numerical models is added in ArcCatalog 9.3. The file was then quality checked in ArcMap to insure values were properly exported to the shapefile from MATLAB. Person who carried out this activity:
    P. Soupy Dalyander
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2290 (voice)
    (508) 457-2310 (FAX)
    sdalyander@usgs.gov
    Data sources used in this process:
    • CONVERGE
    Date: 13-Mar-2017 (process 6 of 7)
    Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Alan O. Allwardt
    Contractor -- Information Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7551 (voice)
    831-427-4748 (FAX)
    aallwardt@usgs.gov
    Date: 29-Mar-2018 (process 7 of 7)
    Keywords section of metadata optimized by correcting variations of theme keyword thesauri and updating/adding keywords. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Arnell S. Forde
    Geologist
    600 4th Street South
    St. Petersburg, FL

    727-502-8000 (voice)
    aforde@usgs.gov
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    The attributes in this data layer correspond to convergences in the maximum (in terms of absolute value) alongshore current velocity in the surf zone for Hh_Dd, characteristics of which may be found in the included wave_scenarios.txt file. Statistical values will vary if a different numerical model is used to estimate the waves and circulation.
  2. How accurate are the geographic locations?
    Numerical models are used in estimating alongshore currents used in creating this data layer. Because the overall horizontal accuracy of the data set depends on the accuracy of the model, the underlying bathymetry, forcing values used, and so forth, the spatial accuracy of this data layer cannot be meaningfully quantified.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    All model output values were used in the calculation of this statistic. The statistic was calculated for a particular scenario (Hh_Dd), the characteristics of which may be found in the included wave_scenarios.txt file. NOTE: Scenarios H3_D6, H4_D5, H4_D12, H4_D13, H5_D4, H5_D5, and H5_D12 do not have convergences, and no GIS files exist in for these cases.The convergences of the maximum (in terms of absolute value) alongshore current in the surf zone were calculated from wave and current estimates generated with Delft3D, and would vary if different models were used or if different model inputs (such as bathymetry, forcing winds, and boundary conditions) or parameterizations were chosen.
  5. How consistent are the relationships among the observations, including topology?
    No duplicate features are present. All polygons are closed, and all lines intersect where intended. No undershoots or overshoots are present.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    P. Soupy Dalyander
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2290 (voice)
    (508) 457-2310 (FAX)
    sdalyander@usgs.gov
  2. What's the catalog number I need to order this data set? Hh_Dd_conv.shp: locations of convergences for the Hh_Dd scenario. NOTE: Specific layer name indicates the scenario (Hh_Dd), with characteristics given in the included wave_scenarios.txt file.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials.
    Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: WinZip archive file containing the shapefile components. The WinZip file also includes FGDC compliant metadata. in format SHP (version 3.3) ESRI shapefile Size: 0.500
      Network links: https://pubs.usgs.gov/of/2012/1234/datafiles.html
    • Cost to order the data: None

  5. What hardware or software do I need in order to use the data set?
    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 29-Mar-2018
Metadata author:
U.S. Geological Survey
Attn: P. Soupy Dalyander
Oceanographer
384 Woods Hole Role
Woods Hole, MA
USA

(508) 548-8700 x2290 (voice)
(508) 457-2310 (FAX)
sdalyander@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/ofr20121234_Hh_Dd_conv.faq.html>
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