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    • Surface ocean radial velocities obtained by HF-radar from stations located along coastal waters of Hawaii, North Slope Alaska, Gulf of Alaska, Puerto Rico/Virgin Islands, eastern U.S./Gulf of America, western U.S., and the Great Lakes

    Metadata Updated: July 1, 2025

    This dataset contains surface ocean radial velocities data obtained by HF-radar from stations located along coastal waters of the United States. Radial velocity files contain metadata in a key-value format, while the measured velocities and associated ancillary data are reported in a tab-delimited format.

    The National Data Buoy Center (NDBC) — in collaboration with the Scripps Institution of Oceanography through June 2025 and thereafter with NOAA’s National Environmental Satellite, Data, and Information Service (NESDIS) — assembles the data from the Integrated Ocean Observing System (IOOS) Surface Currents Program’s High-Frequency (HF) Radar National Network and submits the data on a monthly basis to NOAA’s National Centers for Environmental Information (NCEI).

    Remote sensing of ocean surface velocity from shore-based HF-radar sensors bridges an operational observational gap between point samples obtained from in-situ sampling and synoptic scale relatively low resolution data obtained from satellites by providing continuous mesoscale coverage at relatively high resolution near the coast. HF-radar systems measure the speed of ocean surface currents in directions radial to the antenna in near real time. Radial velocities alone are a measurement of surface ocean velocity projected along the direction radial to the antenna, which only show those currents’ movement towards or away from the HF-radar sensor’s antenna. Radial measurements of ocean velocity may be used directly in some applications such as model assimilation but are commonly used in combination with overlapping sites to estimate the total vector ocean velocity.

    Systems operate continuously in all weather conditions and are installed near the coastline. Range resolution of measured currents is determined by the radar transmit bandwidth used. Bandwidth is controlled by radio frequency licenses and translates to range resolutions of 0.5 to 6 kilometers. Maximum ranges of current measurements also depend on radar transmit frequency and vary from about 40 km offshore to about 200 km offshore. Velocities are measured in the upper 0.3 - 2.5 meters of the ocean depending on the operating frequency and vertical velocity shear profile.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date 2025-06-26T17:58:11Z
    Metadata Created Date February 1, 2025
    Metadata Updated Date July 1, 2025
    Reference Date(s) July 30, 2015 (publication), June 26, 2025 (revision)
    Frequency Of Update monthly

    Metadata Source

    Harvested from NOAA/NESDIS/ncei/accessions

    Other Data Resources

    Graphic Preview

    Preview graphic

    Additional Metadata

    Resource Type Series
    Metadata Date 2025-06-26T17:58:11Z
    Metadata Created Date February 1, 2025
    Metadata Updated Date July 1, 2025
    Reference Date(s) July 30, 2015 (publication), June 26, 2025 (revision)
    Responsible Party (Point of Contact)
    Contact Email
    Guid gov.noaa.nodc:IOOS-HFRadarRadial
    Access Constraints Cite as: NOAA IOOS Surface Currents Program; NOAA National Data Buoy Center (2015). Surface ocean radial velocities obtained by HF-radar from stations located along coastal waters of Hawaii, North Slope Alaska, Gulf of Alaska, Puerto Rico/Virgin Islands, eastern U.S./Gulf of America, western U.S., and the Great Lakes. [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/0mgt-5372. Accessed [date]., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
    Bbox East Long 39.532
    Bbox North Lat 71.3789
    Bbox South Lat -74.262
    Bbox West Long -163.014867
    Coupled Resource
    Frequency Of Update monthly
    Graphic Preview Description Preview graphic
    Graphic Preview File https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:IOOS-HFRadarRadial
    Graphic Preview Type PNG
    Harvest Object Id e805746e-a2ac-49b2-8e9a-a6d5f1149cb7
    Harvest Source Id c084a438-6f6b-470d-93e0-16aeddb9f513
    Harvest Source Title NOAA/NESDIS/ncei/accessions
    Licence accessLevel: Public
    Lineage
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-163.014867, -74.262], [39.532, -74.262], [39.532, 71.3789], [-163.014867, 71.3789], [-163.014867, -74.262]]]}
    Progress onGoing
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2000-03-27

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