/* DATA DESCRIPTION:
Citation:	Dempsey, Britton; Kam, Kitty; Rondón, Anadiuska N; Wallace, Douglas WR; Buchwald, Carolyn (2026): Nitrate concentration and nitrate stable isotopic signatures in seawater in the Labrador Sea in spring 2022 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.986850
Abstract:	Seawater 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.
Keyword(s):	Labrador Sea; nitrate concentration in sea water; stable nitrogen isotope (δ15N)
References:	Granger, Julie; Sigman, Daniel M (2009): Removal of nitrite with sulfamic acid for nitrate N and O isotope analysis with the denitrifier method. Rapid Communications in Mass Spectrometry, 23(23), 3753-3762, https://doi.org/10.1002/rcm.4307
	McIlvin, Matthew R; Casciotti, Karen L (2011): Technical Updates to the Bacterial Method for Nitrate Isotopic Analyses. Analytical Chemistry, 83(5), 1850-1856, https://doi.org/10.1021/ac1028984
Funding:	Natural Sciences and Engineering Research Council (NSERC) (URI: http://www.nserc-crsng.gc.ca/index_eng.asp), grant/award no. NWA-BCP: The Northwest Atlantic Biological Carbon Pump
	Ocean Frontier Institute, grant/award no. NWA-BCP: The Northwest Atlantic Biological Carbon Pump (URI: https://www.ofi.ca/programs/safe-and-sustainable/project/the-northwest-atlantic-biological-carbon-pump)
Coverage:	MEDIAN LATITUDE: 58.677783 * MEDIAN LONGITUDE: -49.290600 * SOUTH-BOUND LATITUDE: 58.483300 * WEST-BOUND LONGITUDE: -49.610100 * NORTH-BOUND LATITUDE: 58.816700 * EAST-BOUND LONGITUDE: -49.110000
	DATE/TIME START: 2022-05-20T16:47:00 * DATE/TIME END: 2022-05-25T14:15:00
	MINIMUM DEPTH, water: 5 m * MAXIMUM DEPTH, water: 2000 m
Event(s):	CE22009_4_Day (CTD_cast_8) * LATITUDE: 58.816700 * LONGITUDE: -49.110000 * DATE/TIME: 2022-05-20T16:47:00 * LOCATION: Labrador Sea * CAMPAIGN: CE22009 (BELAS-1) (URI: https://download.pangaea.de/reference/134405/attachments/nwa-bcp_cruise_report_CE22009.pdf) * BASIS: Celtic Explorer (URI: https://www.marine.ie/site-area/infrastructure-facilities/research-vessels/celtic-explorer) * METHOD/DEVICE: CTD/Rosette (CTD-RO)
	CE22009_6_Day (CTD_cast_11) * LATITUDE: 58.816700 * LONGITUDE: -49.443400 * DATE/TIME: 2022-05-21T16:28:00 * LOCATION: Labrador Sea * CAMPAIGN: CE22009 (BELAS-1) (URI: https://download.pangaea.de/reference/134405/attachments/nwa-bcp_cruise_report_CE22009.pdf) * BASIS: Celtic Explorer (URI: https://www.marine.ie/site-area/infrastructure-facilities/research-vessels/celtic-explorer) * METHOD/DEVICE: CTD/Rosette (CTD-RO)
	CE22009_8_Day (CTD_cast_17) * LATITUDE: 58.650000 * LONGITUDE: -49.610100 * DATE/TIME: 2022-05-23T12:14:00 * LOCATION: Labrador Sea * CAMPAIGN: CE22009 (BELAS-1) (URI: https://download.pangaea.de/reference/134405/attachments/nwa-bcp_cruise_report_CE22009.pdf) * BASIS: Celtic Explorer (URI: https://www.marine.ie/site-area/infrastructure-facilities/research-vessels/celtic-explorer) * METHOD/DEVICE: CTD/Rosette (CTD-RO)
	CE22009_9_Day (CTD_cast_14) * LATITUDE: 58.650000 * LONGITUDE: -49.360100 * DATE/TIME: 2022-05-22T12:28:00 * LOCATION: Labrador Sea * CAMPAIGN: CE22009 (BELAS-1) (URI: https://download.pangaea.de/reference/134405/attachments/nwa-bcp_cruise_report_CE22009.pdf) * BASIS: Celtic Explorer (URI: https://www.marine.ie/site-area/infrastructure-facilities/research-vessels/celtic-explorer) * METHOD/DEVICE: CTD/Rosette (CTD-RO)
	CE22009_11_Day (CTD_cast_21) * LATITUDE: 58.650000 * LONGITUDE: -49.110000 * DATE/TIME: 2022-05-24T11:40:00 * LOCATION: Labrador Sea * CAMPAIGN: CE22009 (BELAS-1) (URI: https://download.pangaea.de/reference/134405/attachments/nwa-bcp_cruise_report_CE22009.pdf) * BASIS: Celtic Explorer (URI: https://www.marine.ie/site-area/infrastructure-facilities/research-vessels/celtic-explorer) * METHOD/DEVICE: CTD/Rosette (CTD-RO)
	CE22009_12_Day (CTD_cast_25) * LATITUDE: 58.483300 * LONGITUDE: -49.110000 * DATE/TIME: 2022-05-25T14:15:00 * LOCATION: Labrador Sea * CAMPAIGN: CE22009 (BELAS-1) (URI: https://download.pangaea.de/reference/134405/attachments/nwa-bcp_cruise_report_CE22009.pdf) * BASIS: Celtic Explorer (URI: https://www.marine.ie/site-area/infrastructure-facilities/research-vessels/celtic-explorer) * METHOD/DEVICE: CTD/Rosette (CTD-RO)
Parameter(s):	Event label (Event) * PI: Buchwald, Carolyn
	Latitude of event (Latitude) * PI: Buchwald, Carolyn
	Longitude of event (Longitude) * PI: Buchwald, Carolyn
	Date/Time of event (Date/Time) * PI: Buchwald, Carolyn
	DEPTH, water [m] (Depth water) * GEOCODE * PI: Buchwald, Carolyn
	Nitrate [µmol/l] ([NO3]-) * PI: Wallace, Douglas WR (douglas.wallace@dal.ca, http://oceanography.dal.ca/person/Wallace_Douglas.html) * METHOD/DEVICE: Automated wet chemistry analyzer, SKALAR, SAN++
	δ15N, nitrate [‰ air] (δ15N NO3) * PI: Buchwald, Carolyn * METHOD/DEVICE: Denitrifier method (McIlvin and Casciotti, 2011); measured with an isotope ratio mass spectrometer (IRMS), Thermo delta V * COMMENT: Vs. 15N of N2 in air
	δ15N, nitrate, standard deviation [±] (δ15N NO3 std dev) * PI: Buchwald, Carolyn * METHOD/DEVICE: Denitrifier method (McIlvin and Casciotti, 2011); measured with an isotope ratio mass spectrometer (IRMS), Thermo delta V * COMMENT: Vs. 15N of N2 in air
	δ18O, nitrate [‰] (δ18O NO3) * PI: Buchwald, Carolyn * METHOD/DEVICE: Denitrifier method (McIlvin and Casciotti, 2011); measured with an isotope ratio mass spectrometer (IRMS), Thermo delta V * COMMENT: Vs. 18O of Vienna standard mean ocean water (VSMOW)
	δ18O, nitrate, standard deviation [±] (δ18O NO3 std dev) * PI: Buchwald, Carolyn * METHOD/DEVICE: Denitrifier method (McIlvin and Casciotti, 2011); measured with an isotope ratio mass spectrometer (IRMS), Thermo delta V * COMMENT: Vs. 18O of Vienna standard mean ocean water (VSMOW)
License:	Creative Commons Attribution 4.0 International (CC-BY-4.0) (URI: https://creativecommons.org/licenses/by/4.0/)
Status:	Curation Level: Enhanced curation (URI: https://wiki.pangaea.de/wiki/Curation_levels)
Size:	345 data points
*/
Event	Latitude	Longitude	Date/Time	Depth water [m]	[NO3]- [µmol/l]	δ15N NO3 [‰ air]	δ15N NO3 std dev [±]	δ18O NO3 [‰]	δ18O NO3 std dev [±]
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	25	2.22	9.91	0.03	8.13	0.09
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	50	4.26	8.11	0.03	6.40	0.23
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	90	12.21	5.53	0.09	2.79	0.07
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	110	13.16	5.15	0.08	2.90	0.07
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	110	13.16	5.02	0.12	2.59	0.04
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	130	13.88	4.78	0.12	2.43	0.26
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	150	14.36	4.81	0.02	2.23	0.03
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	200	14.77	4.78	0.05	2.24	0.04
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	250	14.61	4.75	0.00	2.47	0.29
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	300	14.98	4.78	0.06	1.97	0.40
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	350	15.20	4.72	0.10	2.23	0.16
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	400	15.13	4.84	0.08	2.23	0.16
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	500	15.59	4.79	0.05	2.00	0.12
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	1000	15.92	4.79	0.02	1.89	0.03
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	1500	16.06	4.62	0.07	1.81	0.04
CE22009_4_Day	58.8167	-49.1100	2022-05-20T16:47	2000	16.24	4.75	0.24	2.14	0.03
CE22009_6_Day	58.8167	-49.4434	2022-05-21T16:28	80	13.12	5.05	0.00	2.96	0.09
CE22009_6_Day	58.8167	-49.4434	2022-05-21T16:28	100	13.18	5.11	0.01	2.34	0.11
CE22009_6_Day	58.8167	-49.4434	2022-05-21T16:28	125	13.57	4.73	0.04	2.35	0.01
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	5	2.86	8.75	0.04	6.92	0.11
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	20	2.88	8.73	0.08	6.80	0.33
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	60	9.63	5.86	0.03	3.72	0.22
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	120	13.69	4.91	0.00	2.35	0.07
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	150	14.41	4.65	0.12	2.24	0.09
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	180	14.75	4.58	0.16	2.46	0.41
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	200	14.50	4.72	0.04	2.72	0.05
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	300	14.89	4.52	0.09	2.11	0.02
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	350	15.32	4.67	0.14	2.11	0.00
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	400	15.02	4.47	0.04	2.04	0.00
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	500	14.96	4.49	0.01	2.05	0.00
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	1500	15.79	4.64	0.26	2.17	0.11
CE22009_9_Day	58.6500	-49.3601	2022-05-22T12:28	2000	15.89	4.71	0.39	2.02	0.33
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	80	12.06	5.42	0.02	2.49	0.02
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	100	13.21	5.05	0.06	2.82	0.02
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	120	13.63	4.98	0.09	2.19	0.11
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	135	14.21	4.67	0.04	2.07	0.07
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	150	14.42	4.77	0.05	2.09	0.11
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	150	14.61	4.85	0.07	2.18	0.01
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	200	14.96	4.74	0.14	2.27	0.12
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	250	15.45	4.55	0.14	2.20	0.21
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	350	15.13	4.84	0.11	2.14	0.03
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	400	15.15	4.61	0.04	1.83	0.36
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	1000	16.09	4.76	0.14	2.03	0.02
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	1500	16.11	4.71	0.09	1.82	0.07
CE22009_8_Day	58.6500	-49.6101	2022-05-23T12:14	2000	16.23	4.64	0.08	1.79	0.14
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	5	2.90	9.26	0.12	6.59	0.38
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	15	2.83	9.38	0.01	7.27	0.09
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	25	2.99	9.24	0.05	8.54	0.14
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	120	14.23	4.94	0.15	2.60	0.31
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	150	14.64	4.95	0.08	2.46	0.12
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	180	14.72	4.98	0.04	2.44	0.15
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	200	14.82	4.82	0.13	2.58	0.14
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	1000	15.58	4.85	0.19	1.92	0.19
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	1500	15.70	4.60	0.21	2.16	0.15
CE22009_11_Day	58.6500	-49.1100	2022-05-24T11:40	2000	15.94	4.69	0.11	2.25	0.23
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	5	2.35	9.02	0.03	7.38	0.08
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	30	2.83	9.06	0.06	7.38	0.11
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	70	8.23	6.36	0.08	4.20	0.03
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	105	13.48	5.09	0.01	2.27	0.09
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	125	14.47	4.93	0.12	2.17	0.06
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	180	15.83	4.80	0.11	2.16	0.03
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	200	15.40	4.88	0.00	2.11	0.10
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	250	15.83	4.66	0.31	2.04	0.01
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	350	16.03	4.84	0.04	1.97	0.09
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	400	15.87	4.74	0.23	2.12	0.01
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	500	15.85	4.82	0.07	1.99	0.04
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	1000	16.27	4.74	0.11	1.94	0.11
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	1500	16.45	4.62	0.26	2.07	0.25
CE22009_12_Day	58.4833	-49.1100	2022-05-25T14:15	2000	16.46	4.81	0.01	1.89	0.03