Dataset: Barbados-Bermuda Th-232 Th-230
Deployment: AE1410

Seawater concentrations of dissolved and total Th-232 and Th-230, Barbados to Bermuda

Principal Investigator:

Christopher T. Hayes (University of Southern Mississippi, USM)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Chief Scientist Training Cruise (Barbados-Bermuda, May 2014) (NSF Chief Sci Training Barbados-Bermuda)

Current State:

Final no updates expected

Version:

2016-02-22

Deployment Synonyms:

GAc02

Version Date:

2016-02-22

Data URL:

https://www.bco-dmo.org/dataset-deployment/639022/data

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Description

This dataset was collected as part of a Chief Scientist Training Cruise, May-June 2014. The focus of this research was 'Tracking Saharan dust deposition in the Northwest Atlantic using Th isotopes'. This dataset is GEOTRACES-compliant.

Methods & Sampling

Dataset acquisition description

Water sampling followed GEOTRACES protocols from a standard Niskin Bottle CTD/Rosette (Anderson et al. 2012). 4-5 L water samples were drained or filtered directly from Niskin bottles using Teflon-lined tygon tubing, acidified at sea with ultra-pure 6 molar hydrochloric acid, and analyzed at on-shore at MIT. Analysis involved Fe hydroxide co-precipitation, acid digestion, anion exchange chromatography and isotope dilution inductively-coupled plasma mass spectrometry. Laboratory methods were slightly modified from Anderson et al. (2012) as described by Hayes et al (2015).

References:

Anderson, R. F., M. Q. Fleisher, L. F. Robinson, R. L. Edwards, J. Hoff, S. B. Moran, M. M. Rutgers van der Loeff, A. L. Thomas, M. Roy-Barman, and R. Franois (2012), GEOTRACES intercalibration of 230Th, 232Th, 231Pa, and prospects for 10Be, Limnol. Oceanogr. Methods, 10, 179-213.

Hayes, C. T., R. F. Anderson, S. L. Jaccard, R. François, M. Q. Fleisher, M. Soon, and R. Gersonde (2013), A new perspective on boundary scavenging in the North Pacific Ocean, Earth Planet. Sci. Lett., 369-370(0), 86-97, doi:http://dx.doi.org/10.1016/j.epsl.2013.03.008.

Owens, S. A., K. O. Buesseler, and K. W. W. Sims. "Re-evaluating the 238 U-salinity relationship in seawater: implications for the 238 U-234 Th disequilibrium method." Marine Chemistry 127.1 (2011): 31-39.

Data Processing Description

Dataset Processing Description

Th isotope concentrations are derived from measured Th-232/Th-229 and Th-230/Th-229 ratios as determined by mass spectrometry. The Th-229 spike at MIT was calibrated against a gravimetric Th standard as well as an artificial seawater standard called SWSTD 2010-1, described by Anderson et al. (2012). Corrections for ingrowth of Th-230 from dissolved U-234 during sample storage were made based on measured salinity and the U-salinity relationship of Owens et al. (2011).

The dissolved “excess” Th-230 (Th_230_D_XS) is derived by subtracting from the measured dissolved Th-230 the component sourced from the partial dissolution of lithogenic material based on measured dissolved Th-232 and a lithogenic Th-230/232 atom ratio of 4 x 10-6, as described by Hayes et al. (2013).

BCO-DMO Processing:
- added conventional header with dataset name, PI name, version date
- renamed parameters to BCO-DMO standard
- changed longitude from positive to negative values

Cruise AE1410 was supported by UNOLS and NSF. The sample analysis was supported by the W.O. Crosby post-doctoral fellowship from MIT to Christopher Hayes.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1360666	NSF Division of Ocean Sciences

Instruments

Aerosol Sampler

Supplied Name:

Supplied Description:

Tisch Environmental PM10 aerosol sampler (TE-6070), using 20 cm x 25 cm Whatman41 filter sheets.

Instrument Type

Generic Name: Aerosol Sampler

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/13/

Generic Description:

A device that collects a sample of aerosol (dry particles or liquid droplets) from the atmosphere.

GO-FLO Bottle

Supplied Name:

Supplied Description:

5-L Go-Flo bottle, attached to the ship’s Kevlar line

Instrument Type

Generic Name: GO-FLO Bottle

Acronym: GO-FLO

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

Generic Description:

GO-FLO bottle cast used to collect water samples for pigment, nutrient, plankton, etc. The GO-FLO sampling bottle is specially designed to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths.

Niskin bottle

Supplied Name:

Supplied Description:

ship’s CTD with conventional Niskin bottles

Instrument Type

Generic Name: Niskin bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/

Generic Description:

A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.

Trace element sampler

Supplied Name:

Supplied Description:

MITESS unit

Instrument Type

Generic Name: Trace element sampler

Generic Description:

Automated trace element sampler (MITESS or ATE unit).

Bell, J., J. Betts, and E. Boyle (2002) MITESS: A Moored In-situ Trace Element Serial Sampler for Deep-Sea Moorings, Deep-Sea Research I: 49:2103-2118 (pdf)

More description: http://boyle.mit.edu/~ed/MITESS/MITESShomepage.html

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	cruise identification	unitless	cruise_id
station	station number	unitless	station
sample	sample number derived from cast and bottle numbers	unitless	sample
date_start	date at start of samping	yyyymmdd	date_start
lat_start	starting latitude; north is positive	decimal degrees	lat_start
lon_start	starting longitude; east is positive	decimal degrees	lon_start
press	pressure	decibars	press
depth	depth	meters	depth
temp_ctd	temperature from CTD	degrees Celsius	temp
sal_ctd	salinity from CTD	unitless	sal_ctd
O2_ctd	dissolved oxygen from CTD	umol/kg	O2
BAC	Beam Attenuation Coefficient from the transmissometer	per meter	beam_cp
fluor	fluorescence	arbitrary units	fluor
Th_230_D_CONC_BOTTLE	Dissolved (<0.45 um) Th-230 concentration	uBq/kg	trace_metal_conc
Th_230_D_CONC_BOTTLE_ERR	Dissolved (<0.45 um) Th-230 concentration error	uBq/kg	std_err
Th_230_D_CONC_BOTTLE_FLAG	quality flag: 1 = good; 2 = questionable; 3 = rejected	unitless	flag
Th_230_TD_CONC_BOTTLE	Total dissolvable (from unfiltered water) Th-230 concentration	uBq/kg	trace_metal_conc
Th_230_TD_CONC_BOTTLE_ERR	Total dissolvable (from unfiltered water) Th-230 concentration error	uBq/kg	trace_metal_sd
Th_230_TD_CONC_BOTTLE_FLAG	quality flag: 1 = good; 2 = questionable; 3 = rejected	unitless	flag
Th_232_D_CONC_BOTTLE	Dissolved ((<0.45 um) Th-232 concentration	pmol/kg	trace_metal_conc
Th_232_D_CONC_BOTTLE_ERR	Dissolved ((<0.45 um) Th-232 concentration error	pmol/kg	trace_metal_sd
Th_232_D_CONC_BOTTLE_FLAG	quality flag: 1 = good; 2 = questionable; 3 = rejected	unitless	flag
Th_232_TD_CONC_BOTTLE	Total dissolvable (from unfiltered water) Th-232 concentration	pmol/kg	trace_metal_conc
Th_232_TD_CONC_BOTTLE_ERR	Total dissolvable (from unfiltered water) Th-232 concentration error	pmol/kg	trace_metal_sd
Th_232_TD_CONC_BOTTLE_FLAG	quality flag: 1 = good; 2 = questionable; 3 = rejected	unitless	flag
Th_230_D_XS_CONC_BOTTLE	Dissolved (<0.45 um) Th-230 corrected for lithogenic source	uBq/kg	trace_metal_conc
Th_230_D_XS_CONC_BOTTLE_ERR	Dissolved (<0.45 um) Th-230 corrected for lithogenic source error	uBq/kg	trace_metal_sd
Th_230_D_XS_CONC_BOTTLE_ERR_FLAG	quality flag: 1 = good; 2 = questionable; 3 = rejected	unitless	flag
date_U_separated	The date that uranium was chemically separated from thorium in the sample analysis; used in the ingrowth calculation	yyyymmdd	date

Database

Contribute Data

Dataset: Barbados-Bermuda Th-232 Th-230
Deployment: AE1410

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Barbados-Bermuda Th-232 Th-230Deployment: AE1410

Dataset acquisition description

Dataset Processing Description

Dataset: Barbados-Bermuda Th-232 Th-230
Deployment: AE1410