Dataset: Water Mass Fractions - 39 yrs
Deployment: KN204-01

The fraction of water last ventilated in a given region in a time less than or equal to 39 years ago

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://osprey.bco-dmo.org/dataset-deployment/810852/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_Fraction	fraction of water last ventilated in the LBIR region; LBIR = Labrador and Irminger Seas	unitless (fraction)	no_bcodmo_term
LBIR_Fraction_Uncert	ensemble standard deviation of the LBIR_Fraction	unitless (fraction)	no_bcodmo_term
AONG_Fraction	fraction of water last ventilated in the AONG region; AONG = Arctic Ocean, Greenland, and Norwegian Seas	unitless (fraction)	no_bcodmo_term
AONG_Fraction_Uncert	ensemble standard deviation of the AONG_Fraction	unitless (fraction)	no_bcodmo_term
SPNA_Fraction	fraction of water last ventilated in the SPNA region; SPNA = SubPolar North Atlantic	unitless (fraction)	no_bcodmo_term
SPNA_Fraction_Uncert	ensemble standard deviation of the SPNA_Fraction	unitless (fraction)	no_bcodmo_term
STNA_Fraction	fraction of water last ventilated in the STNA region; STNA = SubTropical North Atlantic	unitless (fraction)	no_bcodmo_term
STNA_Fraction_Uncert	ensemble standard deviation of the STNA_Fraction	unitless (fraction)	no_bcodmo_term
MED_Fraction	fraction of water last ventilated in the MED region; MED = Mediterranean Sea	unitless (fraction)	no_bcodmo_term
MED_Fraction_Uncert	ensemble standard deviation of the MED_Fraction	unitless (fraction)	no_bcodmo_term
NAAD_Fraction	fraction of water last ventilated in the NAAD region; NAAD = North of the Antarctic Divergence	unitless (fraction)	no_bcodmo_term
NAAD_Fraction_Uncert	ensemble standard deviation of the NAAD_Fraction	unitless (fraction)	no_bcodmo_term
SAAD_Fraction	fraction of water last ventilated in the SAAD region; SAAD = South of the Antarctic Divergence	unitless (fraction)	no_bcodmo_term
SAAD_Fraction_Uncert	ensemble standard deviation of the SAAD_Fraction	unitless (fraction)	no_bcodmo_term
OTHER_Fraction	fraction of water last ventilated in the OTHER region; OTHER = the rest of the global sea surface, exluding the other defined areas	unitless (fraction)	no_bcodmo_term
OTHER_Fraction_Uncert	ensemble standard deviation of the OTHER_Fraction	unitless (fraction)	no_bcodmo_term
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 - 39 yrs
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Water Mass Fractions - 39 yrsDeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: Water Mass Fractions - 39 yrs
Deployment: KN204-01