Dataset: Elemental and isotopic noble gas ratios and N2/Ar from the North Atlantic: TTO data

Name: Measurements of Kr/Ar and N2/Ar ratios in stored dissolved gas samples collected in 1981 through the Transient Tracers in the Ocean (TTO) program North Atlantic Survey (NAS)
Published: 2023-02-23
Keywords: noble gas, North Atlantic, nitrogen, gas exchange, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.890427.1

Spatial Extent: N:49.5 E:-11 S:23.3 W:-70.4

Temporal Extent: 1981-04-01 - 1981-10-19

Project:

Collaborative Research: Novel constraints on air-sea gas exchange and deep ocean ventilation from high-precision noble gas isotope measurements in seawater (HPNGI)

Collaborative Research: Probing the Ventilation Efficiency of the Deep Ocean with Conservative Dissolved Gas Tracers in Archived Samples (TTO NGs and O2)

Principal Investigator:

Alan M. Seltzer (Woods Hole Oceanographic Institution, WHOI)

Co-Principal Investigator:

Peter Barry (Woods Hole Oceanographic Institution, WHOI)

William J. Jenkins (Woods Hole Oceanographic Institution, WHOI)

Samar Khatiwala (University of Oxford, Oxford)

David P. Nicholson (Woods Hole Oceanographic Institution, WHOI)

William M. Smethie Jr. (Lamont-Doherty Earth Observatory, LDEO)

Rachel Stanley (Wellesley College)

Martin Stute (Lamont-Doherty Earth Observatory, LDEO)

BCO-DMO Data Manager:

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

Version:

Version Date:

2023-02-23

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Measurements of Kr/Ar and N2/Ar ratios in stored dissolved gas samples collected in 1981 through the Transient Tracers in the Ocean (TTO) program North Atlantic Survey (NAS)

Abstract:

This dataset includes measurements of Kr/Ar and N2/Ar ratios in stored dissolved gas samples collected in 1981 through the Transient Tracers in the Ocean (TTO) program. These data were used, along with new observations of heavy noble gas ratios (elemental and isotopic ratios) from the Bermuda Atlantic Time-series (BATS) on cruise 10391 (30 April 2022 - 05 May 2022), to model simulations of these tracers using the Transport Matrix Method (TMM). Together these new measurements and model simulations provide insight into physical processes governing gas exchange in the high-latitude regions of North Atlantic Deep Water formation, and a comparison of physical simulations of N2/Ar ratios to observations in TTO samples reveals excess N2 that arises from benthic denitrification in the deep North Atlantic.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2023-02-23	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.890427.1	2023-02-24

Methods & Sampling

Note: all methods are described in detail in the accompanying publication currently in final review at Proceedings of the National Academy of Sciences.

Samples were collected via the Transient Tracers in the Ocean (TTO) North Atlantic Survey (NAS) in 1981 via shipboard degassing of ~285-liter Gerard Barrel samples. The extraction technique is described in detail in Smethie and Mathiue (1986). Aliquots of archived gas from these samples were analyzed in the Seltzer and Jenkins Labs at Woods Hole Oceanographic Institution for noble gas elemental ratios and O2/Ar and N2/Ar ratios following techniques described in Seltzer et al. (2023).

The model simulations are available as a related dataset at BCO-DMO. See: https://www.bco-dmo.org/dataset/890293

Data Processing Description

Data Processing:
All data were processed using MATLAB. Codes are available upon request.

BCO-DMO Processing:
- renamed fields to comply with BCO-DMO naming conventions.

Data Files

File
tto_nas_tanks.csv (Comma Separated Values (.csv), 1.11 KB) MD5:7d3245015fcae30e2a3050d1d0ce99d8 Primary data file for dataset ID 890427

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1923915
NSF Division of Ocean Sciences	OCE-2122427

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
TTO	316N19810401 316N19810416 316N19810516 316N19810619 316N19810721 316N19810821 316N19810923	1981-04-01	R/V Knorr		data info

Instruments

Gerard barrel

Supplied Name:

Supplied Description:

Samples were collected via the Transient Tracers in the Ocean (TTO) North Atlantic Survey (NAS) in 1981 via shipboard degassing of ~285-L Gerard Barrel samples

Instrument Type

Generic Name: Gerard barrel

Generic Description:

A barrel used to collect water samples in oceanography. It holds 250 liters of sea water.

Isotope-ratio Mass Spectrometer

Supplied Name: Thermo MAT 253 Plus

Supplied Description:

A Thermo MAT 253 Plus (Seltzer Lab) was used for dynamic noble gas ratios.

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).

Isotope-ratio Mass Spectrometer

Supplied Name: Thermo MAT 253

Supplied Description:

A Thermo MAT 253 (Seltzer Lab) was used for N2, O2, Ar analysis.

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).

Quadrupole Mass Spectrometer

Supplied Name: quadrupole mass spectrometer

Supplied Description:

A custom quadrupole mass spectrometer (Jenkins lab) was used for static noble gas ratios.

Instrument Type

Generic Name: Quadrupole Mass Spectrometer

Acronym: QMS

Generic Description:

A piece of apparatus that consists of an ion source, a mass-to-charge analyser, a detector and a vacuum system and is used to measure mass spectra. The detector is a quadrupole mass-to-charge analyser, which holds the ions in a stable orbit by an electric field generated by four parallel electrodes.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Station	TTO/NAS station number where sample was collected	unitless	station
Depth	Depth of sampling	meters (m)	depth
Lat	Station latitude	degrees North	lat
Lon	Station longitude	degrees East	lon
delta_N2_to_Ar_raw	Δ(N2/Ar),raw: deviation of N2/Ar from solubility equilibrium before physical correction (‰, vs eq)	permil (0/00)	ratio
delta_N2_to_Ar_corr	Δ(N2/Ar),corr: deviation of N2/Ar from solubility equilibrium after physical correction (‰, vs eq)	permil (0/00)	ratio
O2_sat	O2 sat: oxygen concentration relative to solubility equilibrium originally measured in 1981	percent (%)	O2sat
delta_O2_to_Ar	Δ(O2/Ar): deviation of O2/Ar ratio from solubility equilibrium measured in this study (% vs eq)	percent (%)	ratio
Mean_Age_K12	Mean age (K12): ideal mean age (yr) of nearest grid cell in Khatiwala et al., 2012 inversion	years	age
Mean_Age_H21	Mean age (H21): ideal mean age (yr) of nearest grid cell in Holzer et al., 2021 inversion	years	age
delta_Kr_to_Ar_raw	Δ(Kr/Ar),raw: deviation of measured Kr/Ar from solubility equilibrium (‰, vs eq)	permil (0/00)	ratio
delta_Kr_to_Ar_model	Δ(Kr/Ar),model: deviation of modeled Kr/Ar from solubility equilibrium (‰, vs eq)	permil (0/00)	ratio
delta_N2_to_Ar_model	Δ(N2/Ar),model: deviation of modeled N2/Ar from solubility equilibrium (‰, vs eq)	permil (0/00)	ratio

Database

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Dataset: Elemental and isotopic noble gas ratios and N2/Ar from the North Atlantic: TTO data