N01 SUNA - Nitrate Observations Corrected

Metadata Updated: November 12, 2020

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.

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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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Metadata Date March 4, 2020
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) March 4, 2020 (creation)
Frequency Of Update

Metadata Source

Harvested from ioos

Additional Metadata

Resource Type Dataset
Metadata Date March 4, 2020
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) March 4, 2020 (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 -65.91472
Bbox North Lat 42.32584
Bbox South Lat 42.32582
Bbox West Long -65.91474
Coupled Resource [{"href": ["#DataIdentification"], "uuid": [], "title": []}, {"href": ["#DataIdentification"], "uuid": [], "title": []}, {"href": ["#DataIdentification"], "uuid": [], "title": []}]
Frequency Of Update
Metadata Language eng
Metadata Type geospatial
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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