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

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  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?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

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:

   • https://pubs.usgs.gov/of/2012/1234/datafiles.html

   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:

   • https://pubs.usgs.gov/of/2012/1234/

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:

   • http://nomads.ncdc.noaa.gov/data.php

   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:

   • http://polar.ncep.noaa.gov/waves/index2.shtml

   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 8)

   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 8)

   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 8)

   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 8)

   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 8)

   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 8)

   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 8)

   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

   Date: 13-Oct-2020 (process 8 of 8)

   Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Road

   Woods Hole, MA
   

   508-548-8700 x2251 (voice)

   508-457-2310 (FAX)

   vatnipp@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: 13-Oct-2020

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)