10.1594/PANGAEA.986850Dempsey, BrittonBrittonDempsey0009-0003-2353-0602Dalhousie UniversityKam, KittyKittyKamDalhousie UniversityRondón, Anadiuska NAnadiuska NRondónDalhousie UniversityWallace, Douglas WRDouglas WRWallaceDalhousie UniversityBuchwald, CarolynCarolynBuchwaldDalhousie UniversityPANGAEA2026Labrador Seanitrate concentration in sea waterstable nitrogen isotope (δ15N)Event labelLatitude of eventLongitude of eventDate/Time of eventDEPTH, waterNitrateδ15N, nitrateδ15N, nitrate, standard deviationδ18O, nitrateδ18O, nitrate, standard deviationCTD/RosetteAutomated wet chemistry analyzer, SKALAR, SAN++Denitrifier method (McIlvin and Casciotti, 2011); measured with an isotope ratio mass spectrometer (IRMS), Thermo delta VCE22009Celtic Explorer2022-05-20T16:47:00/2022-05-25T14:15:00Dataset10.1002/rcm.430710.1021/ac1028984345 data pointstext/tab-separated-valuesCreative Commons Attribution 4.0 InternationalSeawater was collected for nitrate concentration and stable isotopic analyses between May 20th and May 25th, 2022 aboard RV Celtic Explorer in an area between 58 - 59 degrees N and 49 - 50 degrees W. Nitrate concentration samples were collected from the Niskin unfiltered into 15ml centrifuge tubes and immediately frozen at -20 degrees C. After the survey, these samples were then thawed to room temperature and analyzed using standard colorimetric protocols coupled with a continuous flow nutrient analyzer at the Canada Excellence Research Chairs (CERC) laboratory at Dalhousie University. Sampling for nitrate stable isotopic measurements was conducted by filtering seawater directly from the Niskin-rosette using 0.22 µm polyethersulfone (PES) syringe filters (VWR Cat. no. 76479-018) and collected into 60 mL HDPE bottles, which were then immediately frozen upright at -20 degrees C. Isotopic analyses were prepared in duplicate using the denitrifier method (McIlvin and Casciotti, 2011; doi:10.1021/ac1028984), and analyzed using isotope ratio mass spectrometery (IRMS) on a Thermo Delta V located in the Canada Excellence Research Chairs (CERC) laboratory at Dalhousie University. Samples with detectable nitrite (>0.1 µmol/l) concentrations were first treated with sulfamic acid to remove potential interference on the 15N-NO3 pool as the denitrifier method does not discriminate between nitrate or nitrite (Granger and Sigman, 2009; doi:10.1002/rcm.4307). Isotopic analyses were referenced against USGS32, USGS34, and IAEA-NO3 reference materials.-49.61009999999999-49.11000000000001458.483358.8167Labrador SeaNatural Sciences and Engineering Research Councilhttps://doi.org/10.13039/501100000038NWA-BCPThe Northwest Atlantic Biological Carbon PumpOcean Frontier Institutehttps://doi.org/10.13039/501100010784NWA-BCPThe Northwest Atlantic Biological Carbon Pump