Wave observations from bottom-mounted pressure sensors in Skagit Bay, Washington from Dec 2017 to Feb 2018

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?
   Crosby, Sean C., and Grossman, Eric E., 2019, Wave observations from bottom-mounted pressure sensors in Skagit Bay, Washington from Dec 2017 to Feb 2018: data release DOI:10.5066/P9JZ5F00, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9JZ5F00
   • https://www.sciencebase.gov/catalog/item/5d2914e0e4b038fabe1b3264

   This is part of the following larger work.
   Crosby, Sean C., and Grossman, Eric E., 2019, Wave observations from nearshore bottom-mounted pressure sensors in Skagit and Bellingham Bays, Washington, USA from Dec 2017 to Feb 2018: data release DOI:10.5066/P9JZ5F00, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P9JZ5F00

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -122.550
   East_Bounding_Coordinate: -122.522
   North_Bounding_Coordinate: 48.396
   South_Bounding_Coordinate: 48.335
   

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

   Beginning_Date: 11-Dec-2017

   Ending_Date: 09-Feb-2018

   Currentness_Reference:

   ground condition when data were collected

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: NetCDF files
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (3)
   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 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      
7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   NetCDF files are self-contained and attribute information may be found in the header of the file itself.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. 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)
   • Sean C. Crosby
   • Eric E. Grossman
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

Wave observations were collected as part of the USGS Coastal Climate Impacts Project and development of the Puget Sound Coastal Storm Modeling System (PS-COSMOS) for Puget Sound and the Salish Sea. The wave data help support the validation of the PS-CoSMoS regional wave model for forecasting future extreme high-water levels and flood risk with projected sea-level rise and to characterize the present-day wave climate.

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: 09-Feb-2018 (process 1 of 4)

   Instrumented frames were deployed by hand on December 11, 2017 at 3 locations (S1, S2, S3) from a 17-foot sea Ark skiff and recovered on February 9, 2018. Aluminum frames with a 1-m footprint were equipped with RBR's RBRduo pressure and temperature sensor (early 2015 generation). Mushroom and fluke anchors were attached to frames with chain. Twelve-inch surface floats were attached to anchors for recovery and were not expected to impact instrument recording. Pressure and temperature were recorded continuously at 2Hz during the deployment. Sensor height above bottom was estimated to be 20cm after some settling of the frame in sediment. During deployment and recovery depth was sampled with a handheld sonar and position was recorded with a handheld GPS. The instrument package and mooring system were light enough to deployed and recovered by hand. On February 9, 2018 all instruments were successfully recovered. Person who carried out this activity:
   

   Sean C. Crosby

   Western Washington University

   Oceanographer

   516 High Street

   Bellingham, WA
   

   360-650-4697 (voice)

   sean.crosby@wwu.edu

   Date: 22-Feb-2019 (process 2 of 4)

   After recovery, the manufacturers' software, Ruskin v2.4, was used to download the data. Surface gravity wave properties were estimated from pressure fluctuations following methods developed by Jones and Monismith (2007). Wave properties are estimated under two assumptions, that linear wave theory is valid, and that current speeds are small compared to wave phase velocities. These assumptions may be violated in shallow water depths during large wave events, e.g. wave breaking, and during strong ebb or flood tides. Python 3.0 operating within Windows 10 was used to process the data and scripts are available in the public repository, https://github.com/dnowacki-usgs/stglib. Reference: Jones, N.L., and Monismith, S.G., 2007, Measuring short-period wind waves in a tidally forced environment with a subsurface pressure gauge: Limnology and Oceanography--Methods, v. 5, n. 10, p. 317–327, https://doi.org/10.4319/lom.2007.5.317 Person who carried out this activity:
   

   Sean C. Crosby

   Western Washington University

   Oceanographer

   516 High Street

   Bellingham, WA
   

   360-650-4697 (voice)

   sean.crosby@wwu.edu

   Date: 19-Oct-2020 (process 3 of 4)

   Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 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

   Date: 13-Oct-2021 (process 4 of 4)

   Performed minor edits to the metadata to correct typos. No data were changed. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Susan A. Cochran

   Geologist

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-7545 (voice)

   scochran@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?
   No formal attribute accuracy tests were conducted.
2. How accurate are the geographic locations?
   The stated accuracy of the hand-held GPS unit used to determine instrument position ranged from 3-5 m.
3. How accurate are the heights or depths?
   A formal accuracy assessment of the vertical positional information in the data set has either not been conducted, or is not applicable.
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Data fall within expected ranges.

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:

USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   USA

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? Downloadable time-series are in NetCDF format, containing all relevant metadata. Two zip files are available for download. The first contains continuous temperature and pressure observations recorded by each instrument at sites S1, S2, and S3. The zip file contains a file for each instrument labeled by instrument site (XXb-cal.nc). The second zip contains wave conditions averaged over each 30-min interval. The zip file contains a single file for each instrument labeled similarly (XXs-a.nc). All metadata in NetCDF files is in EPIC compliant format.
3. What legal disclaimers am I supposed to read?

   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Zip file containing continuous temperature and pressure time-series data at all sites in format NetCDF (version 4.7) Size: 273.1
     Network links:	https://www.sciencebase.gov/catalog/file/get/5d2914e0e4b038fabe1b3264name=skagitbay_timeseries.zip https://www.sciencebase.gov/catalog/item/5d2914e0e4b038fabe1b3264 https://doi.org/10.5066/P9JZ5F00

     Data format:	Zip file containing half-hourly wave statistics at all sites in format NetCDF (version 4.7) Size: 3.5
     Network links:	https://www.sciencebase.gov/catalog/file/get/5d2914e0e4b038fabe1b3264?name=skagitbay_wavestatistics.zip https://www.sciencebase.gov/catalog/item/5d2914e0e4b038fabe1b3264 https://doi.org/10.5066/P9JZ5F00

   • Cost to order the data: None

Who wrote the metadata?

Dates:

Last modified: 13-Oct-2021

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

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