Dataset: GP16 Barium Dissolved
Deployment: TN303

Dissolved Barium (Ba) in US GEOTRACES East Pacific Zonal Transect, GP16.

Principal Investigator:

Alan M. Shiller (University of Southern Mississippi, USM)

BCO-DMO Data Manager:

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

Project:

Geotraces Pacific Section: Gallium, vanadium, and associated elements indicative of dust input and redox cycling (EPZT_Ga_V_others)

U.S. GEOTRACES East Pacific Zonal Transect (GP16) (U.S. GEOTRACES EPZT)

Current State:

Final no updates expected

Version:

10 Nov 2016

Deployment Synonyms:

GP16, GEOTRACES EPZT, GEOTRACES East Pacific Zonal Transect (EPZT), GT13, 325020131025

Version Date:

2016-11-10

Data URL:

https://www.bco-dmo.org/dataset-deployment/648757/data

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Description

A section of dissolved Ba concentrations comprised of 36 stations and additional surface water sampling across the Eastern Tropical Pacific from Ecuador to Tahiti.

Methods & Sampling

Dataset acquisition description

Water column samples were taken from the GEOTRACES carousel and filtered through pre-cleaned, 0.2 um Pall Acropak Supor filter capsules as described elsewhere (e.g., Cutter et al., 2012; Hatta et al., 2015). Near surface water samples were collected using an underway towed-fish pumped seawater system (Bruland et al., 2005) with samples filtered through sequential 0.45 um Osmonics and 0.2 µm Polycarbonate (PCTE) cartridge filters. Filtered water was collected in 125 mL HDPE bottles (Nalgene) that had been precleaned by soaking in hot 1.2 M HCl (reagent grade) for at least 8 h with subsequent thorough rinsing with ultrapure distilled deionized water (Barnstead E-pure). Samples were acidified in a laminar flow bench aboard ship using 0.5 mL of ultrapure HCl per 125 mL sample.

Barium was measured using a ThermoFisher Element 2 Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and the isotope dilution method as described by Jacquet et al. (2005). Aliquots (50 uL) of each sample were spiked with 25 uL of a 135Ba-enriched solution (~170 nM) and then diluted 30-fold with 0.2 um ultrapure filtered water. A sample of ~93% enriched 135Ba was obtained from Oak Ridge National Laboratories for use as the enriched isotope spike. The ICP-MS was operated in low resolution and both 135Ba and 138Ba were determined. The samples were bracketed every 10 samples with a blank and the spike 135Ba solution. The volumes of the spikes, samples and dilution water were accurately assessed by calibrating each pipette by weight. The reproducibility error of this method was estimated by comparing samples collected at the same depths on different casts at the same station. For 42 pairs of these replicate samples, the average absolute deviation of 1.4 nmol/kg or typically 1.5%. Repeated runs of runs of US GEOTRACES intercalibration samples and in-house reference solutions suggest a precision of ±2.0%; the limit of detection for barium was 0.7 nmol/kg. Our precision is similar to that reported by other labs for Ba (e.g., Jacquet et al., 2005).

Data Processing Description

Dataset Processing Description

Data quality flags:
2 = Good data;
3 = Questionable data;
4 = Bad data.

Intercalibration:
See the Table 1 Supplement File (.PNG), which lists intercalibration data for reference waters, both our results and results we were able to find from collaborators. Results are reasonably comparable within the 2% precision generally given for Ba analysis. Note that European labs analyzing Ba tend to report values for one of the SLRS reference waters as well as an in house standard. We are hopeful that other data from the BATS crossover station will soon be available to make a better comparison.

BCO-DMO Processing:
- modified parameter names to conform to BCO-DMO and GEOTRACES IDP parameter naming conventions;
- separated Barium columns in _BOTTLE and _FISH, in accordance with the GEOTRACES IDP conventions;
- replaced blanks (missing data) with "nd" ("no data");
- correction made on 10 November 2016: removed duplicate data for sample number 9981;
- 04 March 2019: removed embargo on dataset.

Additional GEOTRACES Processing by BCO-DMO:
As was done for the GEOTRACES-NAT data, BCO-DMO added standard US GEOTRACES information, such as the US GEOTRACES event number, to each submitted dataset lacking this information. To accomplish this, BCO-DMO compiled a 'master' dataset composed of the following parameters: cruise_id, EXPOCODE,SECT_ID, STNNBR, CASTNO, GEOTRC_EVENTNO, GEOTRC_SAMPNO, GEOTRC_INSTR, SAMPNO, GF_NO, BTLNBR, BTLNBR_FLAG_W, DATE_START_EVENT, TIME_START_EVENT, ISO_DATETIME_UTC_START_EVENT, EVENT_LAT, EVENT_LON, DEPTH_MIN, DEPTH_MAX, BTL_DATE, BTL_TIME, BTL_ISO_DATETIME_UTC, BTL_LAT, BTL_LON, ODF_CTDPRS, SMDEPTH, FMDEPTH, BTMDEPTH, CTDPRS, CTDDEPTH.

This added information will facilitate subsequent analysis and inter-comparison of the datasets.

Bottle parameters in the master file were taken from the GT-C_Bottle and ODF_Bottle datasets. Non-bottle parameters, including those from GeoFish tows, Aerosol sampling, and McLane Pumps, were taken from the TN303 Event Log (version 30 Oct 2014). Where applicable, pump information was taken from the PUMP_Nuts_Sals dataset.

A standardized BCO-DMO method (called "join") was then used to merge the missing parameters to each US GEOTRACES dataset, most often by matching on sample_GEOTRC or on some unique combination of other parameters.

If the master parameters were included in the original data file and the values did not differ from the master file, the original data columns were retained and the names of the parameters were changed from the PI-submitted names to the standardized master names. If there were differences between the PI-supplied parameter values and those in the master file, both columns were retained. If the original data submission included all of the master parameters, no additional columns were added, but parameter names were modified to match the naming conventions of the master file.

See the dataset parameters documentation for a description of which parameters were supplied by the PI and which were added via the join method.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1261214	NSF Division of Ocean Sciences

Instruments

CTD Sea-Bird SBE 911plus

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird SBE 911plus

Acronym: CTD SBE 911plus

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0058/

Generic Description:

The Sea-Bird SBE 911 plus is a type of CTD instrument package for continuous measurement of conductivity, temperature and pressure. The SBE 911 plus includes the SBE 9plus Underwater Unit and the SBE 11plus Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 plus and SBE 11 plus is called a SBE 911 plus. The SBE 9 plus uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 plus and SBE 4). The SBE 9 plus CTD can be configured with up to eight auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). more information from Sea-Bird Electronics

GeoFish Towed near-Surface Sampler

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: GeoFish Towed near-Surface Sampler

Acronym: GeoFish

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/31/

Generic Description:

The GeoFish towed sampler is a custom designed near surface (<2m) sampling system for the collection of trace metal clean seawater. It consists of a PVC encapsulated lead weighted torpedo and separate PVC depressor vane supporting the intake utilizing all PFA Teflon tubing connected to a deck mounted, air-driven, PFA Teflon dual-diaphragm pump which provides trace-metal clean seawater at up to 3.7L/min. The GeoFish is towed at up to 13kts off to the side of the vessel outside of the ship's wake to avoid possible contamination from the ship's hull. It was developed by Geoffrey Smith and Ken Bruland (University of California, Santa Cruz).

GO-FLO Teflon Trace Metal Bottle

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: GO-FLO Teflon Trace Metal Bottle

Acronym: GO-FLO Teflon TM

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

Generic Description:

GO-FLO Teflon-lined Trace Metal free sampling bottles are used for collecting water samples for trace metal, nutrient and pigment analysis. The GO-FLO sampling bottle is designed specifically to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	Cruise identification	unitless	cruise_id
cruise_name	Cruise name	unitless	cruise_name
STNNBR	Station number	unitless	station
GEOTRC_EVENTNO	GEOTRACES event number	unitless	event
LATITUDE_PI	Latitude, as reported by the PI.	decimal degrees	lat
LONGITUDE_PI	Longitude, as reported by the PI.	decimal degrees	lon
EVENT_LAT	Latitude at the start of the event (north is positive), from the event log.	decimal degrees	lat
EVENT_LON	Longitude at the start of the event (east is positive), from the event log.	decimal degrees	lon
ISO_DATETIME_UTC_START_EVENT	Date and time, formatted to the ISO 8601 standard, at the start of the sampling event, from the event log.	YYYY-MM-DDTHH:MM:SS[.xx]Z	ISO_DateTime_UTC
CASTNO	Cast number	unitless	cast
GEOTRC_SAMPNO	Unique GEOTRACES sample number	unitless	sample
SMDEPTH	Saunders-Mantyla depth (integrated; uses dynamic height); as reported in the bottle file.	meters	depth
Ba_D_CONC_BOTTLE	Dissolved Barium (Ba) concentration of samples collected by Go-Flo bottles.	nanomoles per kilogram (nmol/kg)	trace_metal_conc
Ba_D_CONC_BOTTLE_FLAG	Quality flag for Ba_D_CONC_BOTTLE. 2 = Good data; 3 = Questionable data; 4 = Bad data.	unitless	flag
Ba_D_CONC_FISH	Dissolved Barium (Ba) concentration of samples collected by GeoFish.	nanomoles per kilogram (nmol/kg)	trace_metal_conc
Ba_D_CONC_FISH_FLAG	Quality flag for Ba_D_CONC_FISH. 2 = Good data; 3 = Questionable data; 4 = Bad data.	unitless	flag
GEOTRC_INSTR	Sampling instrument, from the event log.	unitless	instrument
SAMPNO	Sequential sample number within the cast (usually corresponds to bottle number); from the bottle file.	unitless	bottle
GFISH_NO	GeoFish tow number; from the event log.	unitless	tow
BTLNBR	Bottle number; typically 1-24, from the bottle file.	unitless	bottle
BTLNBR_FLAG_W	Bottle number quality flag reported in the bottle file; follows WOCE conventions. 2 = good; 3 = questionable; 4 = bad; 9 = missing data.	unitless	flag
BTL_ISO_DATETIME_UTC	Date and time, formatted to the ISO 8601 standard, at the time of bottle firing, from the bottle file.	YYYY-MM-DDTHH:MM:SS[.xx]Z	ISO_DateTime_UTC
BTL_LAT	Latitude of bottle firing (north is positive), from the bottle file.	decimal degrees	lat
BTL_LON	Lonitude of bottle firing (east is positive), from the bottle file.	decimal degrees	lon
ODF_CTDPRS	The ODF software acquisition measurement of pressure, from the bottle file.	decibars	press
FMDEPTH	Fofonoff-Millard depth (non-integrated; also used by SBE), from the bottle file.	meters	depth
BTMDEPTH	Bottom depth, from the bottle file.	meters	depth_bottom
CTDPRS	CTD pressure, from the bottle file.	decibars	press
CTDDEPTH	CTD bottle firing depth, from the bottle file.	meters	depth

Database

Contribute Data

Dataset: GP16 Barium Dissolved
Deployment: TN303

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GP16 Barium DissolvedDeployment: TN303

Dataset acquisition description

Dataset Processing Description

Dataset: GP16 Barium Dissolved
Deployment: TN303