Dataset: Water Mass Fractions - Ages
Deployment: KN204-01

Mean ventilation age reported for 7 regions of the Atlantic

Principal Investigator:

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

Co-Principal Investigator:

Mark Holzer (University of New South Wales, UNSW)

Yu-Heng Ting (University of New South Wales, UNSW)

Contact:

Mark Holzer (University of New South Wales, UNSW)

BCO-DMO Data Manager:

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

Project:

Collaborative Research: Completing a 10-Year Record of Deep Western Boundary Current Observations at Line W; A Contribution to the Atlantic Meridional Overturning Circulation Study (DWBC Obs Line W)

RAPID: Continuation of U.S. GEOTRACES North Atlantic Section: CFC and SF6 Measurements (GT NAT RAPID CFC SF6)

U.S. GEOTRACES North Atlantic Section: CFC and SF6 Measurements (GT NAT CFC and SF6)

U.S. GEOTRACES North Atlantic Transect (GA03) (U.S. GEOTRACES NAT)

Deployment Synonyms:

GA03, GT11, KN204-01A, KN204-01B, USGT-NAT-2011, USGNAZT, GNAT, 316N20111106, KN204-1

Data URL:

https://www.bco-dmo.org/dataset-deployment/810899/data

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Description

Water mass fractions and ages calculated from hydrographic and tracer data using a maximum-entropy inversion technique.

This dataset contains the fraction of water last ventilated in a given region in a time less than or equal to 39 years ago as well as the corresponding ensemble standard deviations.

Data File Formats:
For a .csv or .tsv format of these data, use the "Get Data" button at the top of the BCO-DMO metadata page.
For a Matlab file containing all of the water mass fraction data from this project, see the "Data Files" section of the BCO-DMO metadata page.

Methods & Sampling

Dataset acquisition description

A maximum-entropy inversion technique was applied to CFC and SF6 measurements made on the U.S. GEOTRACES North Atlantic Transect, and radiocarbon concentrations interpolated to sample locations along the transact from gridded data reported in the GLODAP data compilation, to determine mean ages and source water compositions of each water sample. Details are described in Holzer et al. (2018).

See the attached README file (GA03_transit-time_partitioned_water-mass_fractions_v2_README.pdf) for more information on methods and a map of region locations.

Data Processing Description

Dataset Processing Description

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0928612	NSF Division of Ocean Sciences
OCE-1132545	NSF Division of Ocean Sciences
OCE-1332834	NSF Division of Ocean Sciences

Instruments

None available yet

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
LBIR_Age	regional mean ventilation age for the LBIR region; LBIR = Labrador and Irminger Seas	years	age
LBIR_Age_Uncert	ensemble standard deviation of LBIR_Age	years	age
AONG_Age	regional mean ventilation age for the AONG region; AONG = Arctic Ocean, Greenland, and Norwegian Seas	years	age
AONG_Age_Uncert	ensemble standard deviation of AONG_Age	years	age
SPNA_Age	regional mean ventilation age for the SPNA region; SPNA = SubPolar North Atlantic	years	age
SPNA_Age_Uncert	ensemble standard deviation of SPNA_Age	years	age
STNA_Age	regional mean ventilation age for the STNA region; STNA = SubTropical North Atlantic	years	age
STNA_Age_Uncert	ensemble standard deviation of STNA_Age	years	age
MED_Age	regional mean ventilation age for the MED region; MED = Mediterranean Sea	years	age
MED_Age_Uncert	ensemble standard deviation of MED_Age	years	age
NAAD_Age	regional mean ventilation age for the NAAD region; NAAD = North of the Antarctic Divergence	years	age
NAAD_Age_Uncert	ensemble standard deviation of NAAD_Age	years	age
SAAD_Age	regional mean ventilation age for the SAAD region; SAAD = South of the Antarctic Divergence	years	age
SAAD_Age_Uncert	ensemble standard deviation of SAAD_Age	years	age
OTHER_Age	regional mean ventilation age for OTHER is not reported because OTHER is the rest of the global sea surface not included in the 7 Atlantic regions	years	age
OTHER_Age_Uncert	ensemble standard deviation of OTHER_Age (not reported)	years	age
Ideal_Mean_Age	estimate of the ideal mean age (regardless of last ventilation location) at each of the 668 bottle locations	years	age
Ideal_Mean_Age_Uncert	ensemble standard deviation of the Ideal_Mean_Age	years	age
Depth	Bottle sample depth	meters (m)	depth
Latitude	Bottle sample latitude	degrees North	lat
Longitude	Bottle sample longitude	degrees East	lon
Distance_East	The distance in kilometers along the combined cruise tracks of the KN199-04 and KN204-01 from the easternmost station (KN204-01 station 1).	kilometers (km)	no_bcodmo_term
Cruise_ID	Cruise identifier	unitless	cruise_id
Station_No	Station number	unitless	station
Cast_No	Cast number	unitless	cast
Sample_Bottle	Bottle number	unitless	bottle
Date	Sampling date; format: yyyymmdd	unitless	date

Database

Contribute Data

Dataset: Water Mass Fractions - Ages
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Water Mass Fractions - AgesDeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: Water Mass Fractions - Ages
Deployment: KN204-01