E01 SUNA - Nitrate Observations Corrected

Metadata Updated: November 12, 2020

Nitrate SUNA V2 sensors (Sea-Bird Scientific) were deployed on NERACOOS Buoy E (Latitude: 43 deg 42.87'N and Longitude: 69 deg 21.36'W) at 50m from June 6, 2015 to November 26, 2018. This time period corresponds to University of Maine buoy deployments E0133, E0134, E0135, E0136, E0137 and E0138 (http://gyre.umeoce.maine.edu/data/gomoos/buoy/html/E01.html). The sensors were programmed to collect nitrate measurements three times per day (0045, 0845 and 1645 GMT) and more recently, eight times day (0045, 0345, 0645, 0945, 1245, 1545, 1845, and 2145 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 15uM. Whenever possible at the time of buoy deployment and recovery, 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 sensor. 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 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 E01_corrected_nitrate_csv
Access Constraints
Bbox East Long -69.35597
Bbox North Lat 43.714503
Bbox South Lat 43.714483
Bbox West Long -69.35599
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 2015-06-06T23:45:00Z
Temporal Extent End 2018-11-26T12:45:00Z

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