Dataset: GT10-11 - Neodymium - LDEO
Deployment: KN204-01

seawater Nd isotopes and concentrations from the US-GEOTRACES North Atlantic zonal transect (NAZT)

Principal Investigator:

Steven L. Goldstein (Lamont-Doherty Earth Observatory, LDEO)

Katharina Pahnke (University of Hawai'i, UH)

Howard Scher (University of South Carolina)

Scientist:

Leopoldo D. Pena (Lamont-Doherty Earth Observatory, LDEO)

Torben Stichel (University of Hawaiʻi at Mānoa, SOEST)

Student:

Brian Duggan (University of South Carolina)

Alison Hartman (Lamont-Doherty Earth Observatory, LDEO)

BCO-DMO Data Manager:

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

Project:

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/780593/data

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Description

These data are from the Lamont-Doherty Earth Observatory (LDEO) of Columbia University.

Please contact the PI for further information.

See also associated data from the University of South Carolina (USC) and the University of Hawaii at Manoa (UH)

Methods & Sampling

Dataset acquisition description

Methodology: A detailed description can be found in Stichel et al. (2015). See the links below for summaries of the described methodology from the paper.

KN199-04 Methodology (pdf)

KN204-01 Methodology (pdf)

Fig. 1: Sample locations for the Intermediate Data Product.

References: (References listed in the data are codes [1], [2], or [3], corresponding with the following publications/manuscripts)

[1] Stichel, T., Hartman, A.E., Duggan, B., Goldstein, S.L., Scher, H., Pahnke, K., 2015. Separating biogeochemical cycling of neodymium from water mass mixing in the Eastern North Atlantic. Earth Planet. Sci. Lett. 412, 245–260. doi:10.1016/j.epsl.2014.12.008

[2] Hartman, A., Goldstein, S., Pena Gonzalez, L. D., Duggan, B., Pahnke, K., Scher, H., Stichel, T., in prep. Seawater neodymium composition in the open ocean North Atlantic: water mass signatures and transport.

[3] Duggan, B., Hartman, A.E., Stichel, T., Goldstein, S.L., Pahnke, K., Bizimis, M., Scher, H., in prep. Neodymium Concentrations and Isotopic Signature of the Deep Western Boundary Current Across Line W

Table 1: Summary of the procedures applied in the involved laboratories of University of Hawaii at Mano (UH), Lamont-Doherty Earth Observatory (LDEO) and University of South Carolina (USC).

Step	UH	LDEO	USC
Pre-concentration	Spiked with ¹⁴⁶Nd prior to co-precipitation with FeOOH (~20mg Fe per sample)	Spiked with ¹⁵⁰Nd prior to co-precipitation with FeOOH (~20mg Fe per sample)	Nd and REE extraction with C18 cartridges, not spiked
Chromatographic separation	2-step separation: 1. 1.4ml AG50W-X8 (200-400µm) as primary column. 2. 0.7ml AG50W-X8 (200-400µm) with Alpha-HIBA to purify Nd. 3. ~100µl TRU-Spec column for removal of any remaining Alpha-HIBA in samples.	2-step separation: 1. 100µl RE-Spec (100-150µm) as primary column. 2. 0.7ml AG50W-X8 (200-400µm) with Alpha-HIBA to purify Nd.	1-step separation: 2ml LN-Spec (50-100µm) for Nd purification. No primary column needed because major ions were removed during pre-concentration
Mass spectrometry	VG-Sector TIMS, NdO+, spiked for simultaneous isotope dilution and composition analysis	VG-Sector54 TIMS, NdO+, spiked for simultaneous isotope dilution and composition analysis	Thermo Neptune Plus MC-ICPMS
Other			Concentrations were determined on a previously separated 500ml aliquot by isotope dilution

Data Processing Description

Dataset Processing Description

Data Processing:
The measured 143Nd/144Nd isotope ratios were normalized to those of the JNdi-1 Nd standard (0.512115, Tanaka et al., 2000). Please see attached methodology files for further information on the data processing.

BCO-DMO Processing Notes:
- Added the sample_GEOTRC column by copying the original sample column and removing the '_2' from sample duplicates.
- Added Cast_ISO_DateTime_UTC from the original date and time fields.

SUMMARY OF CORRECTIONS MADE TO SUBMITTED DATA:

2017-07-17: parameter descriptions revised as per request by R. Anderson: ND_143_ND_144RATIO and int_ND_143_ND_144RATIO.

version 8: The data for version 8 (April 2016) completely replaced those from version 7.
- The quality flag scheme was changed in accordance with ODV.
- New parameters: EPSILON_Nd, EPSILON_ND_FLAG_W, EPSILON_ND_2SD, Instrument, and Reference were added which are described in the documentation.
- Column cruise_part was removed.
- Version 8b: changed quality flags for KN204-01, stations 3 and 8 from 0 to 2

- 07 March 2013: Made the following corrections after consulting with dataset scientist:

KN199-04
-- Changed cast number of event 3176 from 2 to 8.
-- Changed cast number of event 3169 from 8 to 2.
-- Changed event number of KN199-04 station 3 cast 6 from 2059 to 2061.
-- Changed event number of KN199-04 station 7 cast 6 from 2107 to 2132.
-- Changed event number of KN199-04 station 9 cast 3 from 2059 to 2165.
-- Changed event number of KN199-04 station 10 cast 6 from 2191 to 2194.
-- Changed event number of KN199-04 station 11 cast 6 from 2206 to 2208.
-- Changed bottle number of sample #5393 from 5 to 4 (station 5, cast 6).
-- Changed bottle number of sample #5394 from 4 to 3 (station 5, cast 6).
-- Changed time of event #2024 from 2129 to 1202.

KN204-01
-- Changed bottle number of sample #7955 from 8 to 9 (station 22, cast 4).

Additional data and revisions were served 19 Sept. 2013.

version 9: The original dataset was split into three datasets by LAB. LDEO, UH, and USC.
See UH dataset: https://www.bco-dmo.org/dataset/780664
USC dataset: https://www.bco-dmo.org/dataset/3832

Additional GEOTRACES Processing:
After the data were submitted to the International Data Management Office, BODC, the office noticed that important identifying information was missing in many datasets. With the agreement of BODC and the US GEOTRACES lead PIs, 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: station_GEOTRC, cast_GEOTRC (bottle and pump data only), event_GEOTRC, sample_GEOTRC, sample_bottle_GEOTRC (bottle data only), bottle_GEOTRC (bottle data only), depth_GEOTRC_CTD (bottle data only), depth_GEOTRC_CTD_rounded (bottle data only), BTL_ISO_DateTime_UTC (bottle data only), and GeoFish_id (GeoFish data only). 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_GT10, GT-C_Bottle_GT11, ODF_Bottle_GT10, and ODF_Bottle_GT11 datasets. Non-bottle parameters, including those from GeoFish tows, Aerosol sampling, and McLane Pumps, were taken from the Event_Log_GT10 and Event_Log_GT11 datasets. McLane pump cast numbers missing in event logs were taken from the Particulate Th-234 dataset submitted by Ken Buesseler.

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-0926981	NSF Division of Ocean Sciences
OCE-0927241	NSF Division of Ocean Sciences
OCE-0928409	NSF Division of Ocean Sciences

Instruments

CTD Sea-Bird

Supplied Description:

SeaBird CTD, oxygen, fluorescence and transmissometer sensors were attached to the frame in stainless steel or anodized aluminum housings.

Instrument Type

Generic Name: CTD Sea-Bird

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/130/

Generic Description:

Conductivity, Temperature, Depth (CTD) sensor package from SeaBird Electronics, no specific unit identified. This instrument designation is used when specific make and model are not known. See also other SeaBird instruments listed under CTD. More information from Sea-Bird Electronics.

GeoFish Towed near-Surface Sampler

Supplied Name: GeoFish

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).

Mass Spectrometer

Supplied Description:

Neodymium was measured as NdO+ on a VG TIMS Sector ( at UH) and VG TIMS Sector54 ( at LDEO). At USC, the Nd isotope composition was measured on a Thermo Neptune Plus MC-ICPMS.

Instrument Type

Generic Name: Mass Spectrometer

Acronym: Mass Spec

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

General term for instruments used to measure the mass-to-charge ratio of ions; generally used to find the composition of a sample by generating a mass spectrum representing the masses of sample components.

Niskin bottle

Supplied Description:

30L Niskin bottles with Nylon-coated internal stainless steel springs and Viton o-rings, mounted on a powder-coated aluminum frame.

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.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	Official cruise identifier	unitless	cruise_id
cruise_name	agreed nomenclature on cruise section during ODU-GEOTRACES workshop in March 2013	unitless	cruise_name
station_GEOTRC	station number; provided in original data submission	unitless	station
depth_ctd	sampling depth of CTD; also added are depths of surface sampled by GeoFish. Values provided by PI.	meters	depth
depth_GEOTRC_CTD_round	sampling depth rounded to nearest meter	meters	depth
cast_GEOTRC	cast number	unitless	cast
event_GEOTRC	event number; provided in original data submission	unitless	event
date	date of cast; UTC	yyyymmdd	date
time	time of collection; UTC	HHMM	time
sample_bottle_GEOTRC	Unique identification numbers given to samples taken from bottles; ranges from 1 to 24; often used synonymously with bottle number. nd bottles were from surface GeoFish. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	unitless	sample
BTL_ISO_DateTime_UTC	Date and time (UTC) variable recorded at the bottle sampling time in ISO compliant format. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	YYYY-MM-DDTHH:MM:SS[.xx][+/-TZ]	ISO_DateTime_UTC
lat	latitude; North is positive.Values were added from the intermediate US GEOTRACES master file (see Processing Description).	decimal degrees	lat
lon	longitude; East is positive.Values were added from the intermediate US GEOTRACES master file (see Processing Description).	decimal degrees	lon
sample_GEOTRC	GEOTRACES sample number; provided in original data submission. Values were added from the intermediate US GEOTRACES master file (see Processing Description) and match those provided by PI.	unitless	sample
ND_143_ND_144RATIO	Final atom ratio of 143Nd/144Nd after correcting mass bias and instrumental offset	unitless	Nd143_144
ND_143_ND_144_FLAG_W	Quality flag: Flag 0: good value; Flag 1: no value or unknown value; Flag 2: replacement considered good value; Flag 4: not trusted; -999: missing value	unitless	flag
int_ND_143_ND_144RATIO	Standard error of the mean using standard deviation divided by the square root of ratios in one measurement (e.g. UH used normally 378 ratios for one measurement)	unitless	Nd143_144
EPSILON_Nd	final 143Nd/144Nd normalized to 0.512638 (143Nd1/44Nd of the Chondritic Uniform Reservoir in Jacobsen and Wasserburg - 1980) in parts per 10000.	parts per 10000	no_bcodmo_term
EPSILON_ND_FLAG_W	Quality flag: Flag 0: good value; Flag 1: no value or unknown value; Flag 2: replacement considered good value; Flag 4: not trusted; -999: missing value	unitless	flag
EPSILON_ND_2SD	2 standard deviations of the repeatedly measured standards during the analysis	parts per 10000	std_dev
diss_Nd_pmol_kg	dissolved Nd concentration	pmol/kg	Nd
REE_ND_UH_FLAG_W	Quality flag: Flag 0: good value; Flag 1: no value or unknown value; Flag 2: replacement considered good value; Flag 4: not trusted; -999: missing value	unitless	flag
LAB	the lab group that analyzed the sample: LDEO = Lamont-Doherty Earth Observatory: UH = Univ. of Hawaii; USC = Univ. of South Carolina	unitless	no_bcodmo_term
Instrument	instrument used for analysis: TIMS: Thermal ionization mass spectrometer (VG-Sector (UH) or VG-Sector54 (LDEO)); ICPMS: Multi-Collector Inductively Coupled Mass Spectrometer (NeptunePlus)	unitless	instrument
Reference	Publication reference; see Description for details	unitless	reference_paper

Database

Contribute Data

Dataset: GT10-11 - Neodymium - LDEO
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GT10-11 - Neodymium - LDEODeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: GT10-11 - Neodymium - LDEO
Deployment: KN204-01