Dataset: Nitrate isotopes
Deployment: KN192-05

Nitrate dual isotope (d15N and d18O) measurements.

Principal Investigator:

Karen L. Casciotti (Stanford University)

Co-Principal Investigator:

Caitlin Frame (University of Basel (Universitat Basel))

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Cobalt, Iron and Micro-organisms from the Upwelling zone to the Gyre (GAc01) (CoFeMUG)

Current State:

Final no updates expected

Version:

28 Dec 2015

Deployment Synonyms:

GAc01, CoFeMUG, KN192-5

Version Date:

2015-12-28

Data URL:

https://www.bco-dmo.org/dataset-deployment/630253/data

Expand/Collapse All

Description

Nitrate dual isotope (d15N and d18O) measurements made from samples from acid-cleaned, Teflon-coated X-Niskin sampling bottles on the CoFeMUG cruise (KN192-05).

Methods & Sampling

Dataset acquisition description

Single water samples for nitrate isotopic analyses were collected from acid-cleaned, Teflon-coated X-Niskin sampling bottles (OceanTest Equipment) of 8-liter capacity deployed on an epoxy-coated rosette (Sea-Bird Electronics) rosette as described in Noble et al. (2012). Samples were collected into triple-rinsed 60 mL HDPE bottles and stored frozen at -20 degrees C until analysis. Isotopic analyses of NO3 were made with a Finnigan DELTA PLUS XP IRMS using the denitrifier method (Sigman et al., 2001; Casciotti et al., 2002; McIlvin and Casciotti, 2011). Both d15N-NO3 and d18O-NO3 analyses were made in duplicate and data are reported as means +/- 1 standard deviation.

Data Processing Description

Dataset Processing Description

Data Processing:
Samples were calibrated on the atmospheric N2 (d15N) and VSMOW (d18O) reference scales using nitrate isotope reference materials USGS-32, USGS-34, and USGS-35 (Bohlke et al., 2003), analyzed in replicate with each batch of samples (McIlvin and Casciotti, 2011).

BCO-DMO Processing Notes:
- Modified original parameter names to conform with BCO-DMO naming conventions;
- Missing values (blank) were replaced with 'nd' to indicate 'no data';
- Calculated lon from original lon_360 field;
- 28 Feb 2018: removed emargo on dataset.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0452883	NSF Division of Ocean Sciences
OCE-0752291	NSF Division of Ocean Sciences
OCE-0928414	NSF Division of Ocean Sciences
OCE-1031271	NSF Division of Ocean Sciences

Instruments

Isotope-ratio Mass Spectrometer

Supplied Name: Finnigan DELTA PLUS XP IRMS

Supplied Description:

Isotopic analyses of NO3 were made with a Finnigan DELTA PLUS XP IRMS using the denitrifier method.

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).

Trace Metal Bottle

Supplied Name: Teflon-coated X-Niskin sampling bottles (OceanTest Equipment)

Supplied Description:

Instrument Type

Generic Name: Trace Metal Bottle

Acronym: TM Bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/30/

Generic Description:

Trace metal (TM) clean rosette bottle used for collecting trace metal clean seawater samples.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	Official cruise identifier.	dimensionless	cruise_id
sta	Station number.	dimensionless	sta
lat	Latitude; North is positive.	decimal degrees	lat
lon	Longitude; East is positive. Calculated by BCO-DMO from the original PI-provided lon_360 values.	decimal degrees	lon
lon_360	Longitude measured from 0 to 360 degrees.	decimal degrees	lon_360
press	Pressure.	decibars (db)	press
ev_code	Event code; type and number of sampling event; matches cruise event log.	dimensionless	ev_code
event	Event number from the cruise event log.	dimensionless	event
d15N_NO3	d15N-NO3 = ([15N]/[14N]NO3 / [15N]/[14N]standard -1) x 1000‰; referenced to atmospheric N2.	per mil (‰)	dN15_NO3
d15N_NO3_stdev	Standard deviation (in per mil units) of replicate d15N-NO3 analyses.	per mil (‰)	std_dev
d18O_NO3	d18O-NO3 = ([18O]/[16O]NO3 / [18O]/[16O]standard -1) x 1000‰; referenced to VSMOW	per mil (‰)	d18O_NO3
d18O_NO3_stdev	Standard deviation (in per mil units) of replicate d18O-NO3 analyses.	per mil (‰)	std_dev

Database

Contribute Data

Dataset: Nitrate isotopes
Deployment: KN192-05

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Nitrate isotopesDeployment: KN192-05

Dataset acquisition description

Dataset Processing Description

Dataset: Nitrate isotopes
Deployment: KN192-05