SWASH Model Water Level Time Series at Wrightsville Beach, NC, USA for ILM site

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?
   Birchler, Justin J., Palmsten, Margaret L., Doran, Kara S., Karwandyar, Sharifa, Pardun, Joshua M., Oades, Elora M., Mulligan, Ryan P., and Whitehead-Zimmers, Eli S., 20240903, SWASH Model Water Level Time Series at Wrightsville Beach, NC, USA for ILM site:.

   This is part of the following larger work.
   Birchler, Justin J., Palmsten, Margaret L., Doran, Kara S., Karwandyar, Sharifa, Pardun, Joshua M., Oades, Elora M., Mulligan, Ryan P., and Whitehead-Zimmers, Eli S., 20240903, SWASH Model Water Level Time Series at Wrightsville Beach, NC during Hurricane Isaias, August 2020: U.S. Geological Survey data release doi:10.5066/P14FO5GC, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

   Online Links:

   • https://doi.org/10.5066/P14FO5GC

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -77.7892475582139
   East_Bounding_Coordinate: -77.768820114813
   North_Bounding_Coordinate: 34.2159233494084
   South_Bounding_Coordinate: 34.2026634213659
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 03-Aug-2020

   Ending_Date: 04-Aug-2020

   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: Atlantic Ocean
      

      This is a Vector data set. VPF Topology level 3
      It contains the following vector data types (VPF terminology):
      • Face (957)
   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 18
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -75.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      

      Planar coordinates are encoded using Coordinate Pair
      Abscissae (x-coordinates) are specified to the nearest 1.927269
      Ordinates (y-coordinates) are specified to the nearest 1.592312
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.25722210100002.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 0.0001
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: attribute values
      

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   ILM_SWASH_Output.nc: Modeled water level time series data simulated for 03 August 2020, to 04 August 2020, at Wrightsville Beach, North Carolina (site ILM-1264). The location and elevation data are provided in vector format in a NetCDF file (.nc). The NetCDF file contains the following variables: world coordinates of the model transect (Easting and Northing), horizontal and vertical coordinates of the model transect (x and z), model timestep (timeStep), input tide value for each simulation (tide), start time of each simulation (timeStart) and water level time series for each of the ten simulations (tideEtaT#). The Climate and Forecast (CF)-compliant metadata (version CF-1.6) in the header of the NetCDF file provides spatial information for projecting the data into a geographic information system (GIS). It also provides information about the conventions used for attributes in the dataset.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

   Entity_and_Attribute_Overview:

   SWASH_Input_example.zip: Example of SWASH model input files used for the cross-shore profile at Wrightsville Beach, North Carolina for model run initiated at 2300 GMT on 3 August 2020: A) SWASH initialization file (swashinit.txt), B) SWASH command file (PIER_202008_0323.sws), C) Input bathymetry for the PIER profile (PIER_bathy.txt), and D) Input wave spectral energy (T1_0323_2Dspec.txt). The text files contain all information needed to initiate the SWASH model. The SWASH command files for all profiles and times were identical except for the input tide elevation (LEVEL), input bathymetry which, varied slightly between profiles, and spectral wave input, which varied between times.

   Entity_and_Attribute_Detail_Citation:

   Delft University of Technology. The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Justin J. Birchler
   • Margaret L. Palmsten
   • Kara S. Doran
   • Sharifa Karwandyar
   • Joshua M. Pardun
   • Elora M. Oades
   • Ryan P. Mulligan
   • Eli S. Whitehead-Zimmers
2. Who also contributed to the data set?
   U.S. Geological Survey
3. To whom should users address questions about the data?
   U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center

   Attn: Justin J. Birchler

   Physical Scientist

   600 4th Street South

   Saint Petersburg, FL
   

   727-502-8019 (voice)

   jbirchler@usgs.gov

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?

   Date: 01-Nov-2023 (process 1 of 2)

   A hindcast model simulated the hydrodynamic conditions from the landfall of Hurricane Isaias in August 2020 along the North Carolina, USA coast (Manchia and Mulligan, 2022). The hydrodynamic model Delft3D was coupled with the spectral wave model SWAN (Simulating WAves Nearshore) to span the coastal region of Onslow Bay and its surrounding continental shelf offshore of Wrightsville Beach. The SWAN model was forced with water level boundary conditions defined by tide gages located at Duck, NC (NOAA station 8651370, https://tidesandcurrents.noaa.gov/stationhome.html?id=8651370) and at Charleston, South Carolina (SC) (NOAA station 8665530, https://tidesandcurrents.noaa.gov/stationhome.html?id=8665530). The Simulating WAves till SHore (SWASH) model (Zijlema and others, 2011) was used to simulate wave and water level interactions with the shore. Hourly directional energy spectra produced by Manchia and Mulligan (2022) were output at the offshore boundary of the SWASH domain (water depth = 13.5 m). Ten hours around the peak of the storm were simulated to capture the evolution and maximum water levels of Hurricane Isaias, 23:00 GMT on 3 August 2020 to 09:00 GMT on 4 August 2020. Wave energy was propagated over a 1-Dimensional bathymetric transect, which is included in the USGS-NOAA Total Water Level and Coastal Change Forecast (Stockdon and others, 2023) region for Wilmington, NC (ILM), at site ILM-1264, located 372 m southwest of a local pier at Wrightsville Beach, NC. The SWASH computational grid extends 2390.0 m and has a cross-shore horizontal resolution of 2.5 m. The transect was repeated in the alongshore to have 5 grid points, spanning 20 m (delta-y = 4 m) to accommodate directional energy inputs. Input spectral files had 42 frequency bins between f = 0.04:0.4 hertz (Hz) and had a directional resolution of 5 degrees. The wave field was initialized with all current and velocity components set to zero and a mean water level equal to the corresponding verified water level at the tide gauge at Wrightsville Beach, NC (NOAA station 8658163, https://tidesandcurrents.noaa.gov/stationhome.html?id=8658163). Each simulation was run for a total of 60 minutes with the first 15 minutes allocated for spinup time as the domain reached steady-state. Data were output at a time step of 0.5 seconds (s), but the model internally computed variables at a dynamic time step ranging between 0.04 and 0.08 s, governed by the Courant number. The horizontal viscosity was taken as constant, and a standard k-epsilon model was used in the vertical direction. Default model values were used for the Courant number, the breaking threshold, and in the calculation of bottom friction, which included a constant Manning coefficient (Zijlema and others, 2011). The resulting water level elevations, extracted at the end of each simulation, were output into MATLAB data files. For further information regarding model input generation and visualization of model output topography and bathymetry, refer to Birchler and others (2024). Person who carried out this activity:
   

   Justin J. Birchler

   U.S. Geological Survey

   Physical Scientist

   600 4th Street S

   St. Petersburg, Florida
   

   USA

   (727)-502-8019 (voice)

   jbirchler@usgs.gov

   Date: 01-Apr-2024 (process 2 of 2)

   Modeled water level outputs were extracted in Mathworks MATLAB (R2023a) and were packaged into a NetCDF file (.nc), using the export functions available in MATLAB, for inclusion in this data release. The output data file is a time series of ten hours of simulated water levels from 2300 GMT on August 3, 2020, to 0900 GMT on August 4, 2020, during the landfall of Hurricane Isaias. See the entity and attribute information section for more information about this dataset. Person who carried out this activity:
   

   Justin J. Birchler

   U.S. Geological Survey

   Physical Scientist

   600 4th Street South

   Saint Petersburg, Florida
   

   727-502-8019 (voice)

   jbirchler@usgs.gov

   Data sources produced in this process:

   • ILM_SWASH_Output.nc

3. What similar or related data should the user be aware of?
   Birchler, J.J., Palmsten, M.L., Doran, K.S., Karwandyar, S., Pardun, J.M., Oades, E.M., Mulligan, R.P., and Whitehead-Zimmers, E.S., 202410, Skill assessment of a total water level and coastal change forecast during the landfall of a hurricane: Coastal Engineering Volume 193 (October 2024) 104590.

   Online Links:

   • https://doi.org/10.1016/j.coastaleng.2024.104590

   Zijlema, M., Stelling, G., and Smit, P., 20110702, SWASH: An operational public domain code for simulating wave fields and rapidly varied flows in coastal waters: Coastal Engineering Volume 58, Issue 10.

   Online Links:

   • https://doi.org/10.1016/j.coastaleng.2011.05.015

   Other_Citation_Details: Pages 992-1012
   

   Manchia, C.M., and Mulligan, R.P., 20220315, Hurricane wind-driven surface waves on a narrow continental shelf and exposed coast: Continental Shelf Research Volume 237 (2022) 104681.

   Online Links:

   • https://doi.org/10.1016/j.csr.2022.104681

   Stockdon, H.F., Long, J.W., Palmsten, M.L., Van der Westhuysen, A., Doran, K.S., and Snell, R.J., 20230517, Operational forecasts of wave-driven water levels and coastal hazards for US Gulf and Atlantic coasts: Communications Earth & Environment Volume 4, Article 169 (2023).

   Online Links:

   • https://doi.org/10.1038/s43247-023-00817-2

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?
   This file contains the topographic and bathymetric elevations that were input into the SWASH model to simulate water level time series. Within the SWASH model, the coordinates are projected to the North American Datum 1983 (NAD83), Universal Transverse Mercator (UTM) Zone 18 North (18N) coordinate system.
3. How accurate are the heights or depths?
   Vertical datum is projected to the North American Vertical Datum of 1988 (NAVD88) with an estimated resolution of 0.01 meters (m).
4. Where are the gaps in the data? What is missing?
   This model output contains the complete time series of water levels for ten simulations. This dataset is considered complete for the information presented, as described in the abstract section. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   The water level time series dataset simulates the model-derived water levels for ten hours along the model transect.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center

   Attn: USGS SPCMSC Data Management

   600 4th Street South

   Saint Petersburg, FL
   

   United States

   727-502-8000 (voice)

   gs-g-spcmsc_data_inquiries@usgs.gov
2. What's the catalog number I need to order this data set? ILM_SWASH_Output.nc
3. What legal disclaimers am I supposed to read?
   This digital publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	ILM_SWASH_Output.nc is a NetCDF file that contains the final model water level elevations and coordinate information, in meters. in format NetCDF (version NetCDF version 4.8.1)
     Network links:	https://coastal.er.usgs.gov/data-release/doi-P14FO5GC/data/ILM_SWASH_Output.zip https://coastal.er.usgs.gov/data-release/doi-P14FO5GC/data/SWASH_Input_example.zip

   • Cost to order the data: None

Who wrote the metadata?

Dates:

Last modified: 03-Sep-2024

Metadata author:

U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center

Attn: USGS SPCMSC Data Management

600 4th Street South

Saint Petersburg, FL

United States

727-502-8000 (voice)

gs-g-spcmsc_data_inquiries@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)