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    • N01 SUNA - Nitrate Observations Corrected

    Metadata Updated: February 27, 2026

    One SUNA V2 and two ISUS (Sea-Bird Scientific) were deployed on NERACOOS Buoy N (Latitude: 42 deg 19.48'N and Longitude: 65 deg 54.55'W) at 50m, 100m and 180m, respectively, from July 26, 2016 to July 15, 2017. This corresponds to University of Maine buoy deployment N0120 (http://gyre.umeoce.maine.edu/data/gomoos/buoy/html/N01.html). The sensors were programmed to collect nitrate measurements three times per day (0045, 0845 and 1645 GMT) over a fixed sampling window of 30 seconds at approximately 1.4 readings per second. Five measurements recorded in the middle of the 30 second data stream were transmitted back to the University of Maine Physical Oceanography Group via cell phone. The mean concentration and standard deviation were calculated for each specific sampling time. If the standard deviation for a mean was greater than 2uM, the values were eliminated. Surviving data were then quality controlled (QCed) by removing outliers assessed as values less than -0.5uM and greater than 30uM. At the time of buoy deployment, a standard CTD cast was conducted with a carrousel water sampler equipped with Niskin bottles. Ground truth water samples were collected at the same depth as the nitrate sensors. These samples were analyzed for nitrate concentrations at the University of Maine using a Bran Luebbe AA3 Autoanalyzer and standard techniques. Ground truth corrections were added or subtracted as an offset only if the difference between the nitrate concentration of the water sample collected and the mean nitrate sensor reading at approximately the same time was greater than 2 uM. Upon recovery of the instruments, the data was processed using the software provided by Sea-Bird (UCI and ISUS.com) and compared with the real-time measurements as a check for accuracy. In the event that the sensor was not able to transmit in real-time, the processed data was QCed. Please contact David Townsend, University of Maine, School of Marine Sciences if you have any questions.

    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.

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    Dates

    Metadata Date January 27, 2026
    Metadata Created Date May 15, 2021
    Metadata Updated Date February 27, 2026
    Reference Date(s) January 27, 2026 (creation)
    Frequency Of Update

    Metadata Source

    Harvested from ioos

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Date January 27, 2026
    Metadata Created Date May 15, 2021
    Metadata Updated Date February 27, 2026
    Reference Date(s) January 27, 2026 (creation)
    Responsible Party University of Maine School of Marine Sciences (Point of Contact)
    Contact Email
    Guid N01_corrected_nitrate_csv
    Access Constraints
    Bbox East Long -65.91473
    Bbox North Lat 42.32583
    Bbox South Lat 42.32583
    Bbox West Long -65.91473
    Coupled Resource [{"title": [], "href": ["#DataIdentification"], "uuid": []}, {"title": [], "href": ["#DataIdentification"], "uuid": []}, {"title": [], "href": ["#DataIdentification"], "uuid": []}]
    Frequency Of Update
    Harvest Object Id 4e5e82f9-8f73-4593-88dd-5d26b811bfe3
    Harvest Source Id 54e15a6e-6dde-4c9c-a8f0-345cc0dfccfb
    Harvest Source Title ioos
    Licence
    Lineage
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Point", "coordinates": [-65.91473, 42.32583]}
    Progress
    Spatial Data Service Type ERDDAP tabledap
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2016-07-26T08:45:00Z
    Temporal Extent End 2017-07-15T16:45:00Z

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