Dataset: GN01 Silicon Stable Isotopes

Name: Depth profiles of the isotopic composition (d30Si) of silicon within dissolved silicic acid on the US GEOTRACES Arctic cruise GN01 (HLY1502) from August to October 2015
Published: 2020-04-17
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.809612.1

Spatial Extent: N:89.9876 E:179.3519 S:65.8093 W:-179.8086

Temporal Extent: 2015-08-16 - 2015-10-07

Project:

GEOTRACES Arctic Section: Diagnosing the unique silicon isotope composition of the Arctic Ocean (GEOTRACES Arctic Si Isotopes)

U.S. Arctic GEOTRACES Study (GN01) (U.S. GEOTRACES Arctic)

Program:

U.S. GEOTRACES (U.S. GEOTRACES)

Principal Investigator:

Mark A. Brzezinski (University of California-Santa Barbara, UCSB-MSI)

Contact:

Janice L. Jones (University of California-Santa Barbara, UCSB)

BCO-DMO Data Manager:

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

Version:

Version Date:

2020-04-17

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Depth profiles of the isotopic composition (d30Si) of silicon within dissolved silicic acid on the US GEOTRACES Arctic cruise GN01 (HLY1502) from August to October 2015

Abstract:

The isotopic composition of dissolved silicon (δ30Si) has proven to be a powerful tool to better understand the marine Si cycle. The δ30Si of seawater carries information about DSi utilization in surface waters, the subsequent dissolution of sinking biogenic material as well as water mass mixing. This data set supplies information on the spatial distribution of isotopes of Si within water masses in the Arctic Ocean from the Bering Strait to the north pole. Profiles of silicon isotopes within silicic acid, δ30Si(OH)4, were obtained at a total of 15 stations on the GEOTRACES GN01 cruise

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2020-04-17	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.809612.1	2020-04-20

Methods & Sampling

Samples collected from Niskin bottles using the GEOTRACES ODF CTD-rosette system. (Note on niskin trip depths reported in dataset: multiple bottles were tripped to collect sample water; these samples were linked to the Niskin number having both oxygen and salinity bottle data.)

Seawater samples for δ30Si measurements were collected using a Oceanographic Data Facilitiy’s (ODF, Scripps Institution of Oceanography) CTD-rosette mounted with Niskin samplers and a Sea-Bird Electronics CTD (SBE9plus). Seawater was gravity filtered into polypropylene containers through in-line Supor filter capsules (0.8/0.45 µm) attached directly to each Niskin bottle. Sample bottles were capped and stored without preservative in the dark.

Back in the laboratory, the silicon from seawater was precipitated of as trimethylamine silicomolybdate using a high purity triethlyamine ammonium molybdate solution (TEA-Moly). The precipitate was isolated by filtration onto a polycarbonate filter and purified by high temperature combustion to produce solid silicon dioxide. SiO2 was then converted to solid Cs2SiF6 by dissolution in HF and addition of CsCl. The Cs2SiF6 was rinsed with ethanol, dried and dissolved in high purity (>18MΩ) water. BaSiF6 was precipitated by the addition of BaCl, rinsed with ethanol and dried.

Isotopic ratio analysis was performed using a Nu Perspective isotope ratio mass spectrometer equipped with a Nu Sil inlet system. Samples as BaSiF6 are loaded into sample vials that are placed in a sample carousel in the Nu Sil. Samples are sequentially heated to 590°C.

Isotope delta values are normalized against the international standard NBS28.

For more information, see the Protocol document (under Supplemental Files).

Data Processing Description

Data are flagged with the following quality flags:
1 Good = Passed documented required QC tests;
2 = Not evaluated, not available or unknown: Used for data when no QC test performed or the information on quality is not available;
3 = Questionable/suspect: Failed non-critical documented metric or subjective test(s);
4 = Bad: Failed critical documented QC test(s) or as assigned by the data provider;
9 = Missing data: Used as place holder when data are missing.

BCO-DMO Processing:
- modified parameter names;
- formatted dates to yyyy-mm-dd and times to HH:MM;
- added date/time fields in ISO 8601 format.

Data Files

File
Si_isotopes.csv (Comma Separated Values (.csv), 32.96 KB) MD5:b7b054b6191707d6aa97e6c0425614ec Primary data file for dataset ID 809612

Supplemental Files

File
Brzezinski Lab Si Natural Abundance Protocols filename: Natural_Abundance_Protocol.pdf (Portable Document Format (.pdf), 132.70 KB) MD5:eef6447879df1c705bd3a8858177e388 Brzezinski Lab Si Natural Abundance Preparation Protocols

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1434305

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
HLY1502	GN01 U.S. GEOTRACES Arctic 32H120150809	2015-08-09	USCGC Healy	David C. Kadko (Chief Scientist) William M. Landing (Co-Chief Scientist)	data info

Instruments

CTD Sea-Bird

Supplied Name: SBE9plus

Supplied Description:

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.

Isotope-ratio Mass Spectrometer

Supplied Name: Nu Perspective isotope ratio mass spectrometer

Supplied Description:

Isotopic ratio analysis was performed using a Nu Perspective isotope ratio mass spectrometer equipped with a Nu Sil inlet system.

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

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

Generic Description:

The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).

Niskin bottle

Supplied Name:

Supplied Description:

Samples were collected from Niskin bottles using the GEOTRACES ODF CTD-rosette system.

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

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Station_ID	Sampling station	unitless	station
Start_Date_UTC	CTD start date (UTC); format: yyyy-mm-dd	unitless	date
Start_Time_UTC	CTD start time (UTC); format: HH:MM	unitless	time
Start_ISO_DateTime_UTC	CTD start date and time (UTC) in ISO8601 format: yyyy-mm-ddTHH:MMZ	unitless	ISO_DateTime_UTC
End_Date_UTC	CTD end date (UTC); format: yyyy-mm-dd	unitless	date
End_Time_UTC	CTD end time (UTC); format: HH:MM	unitless	time
End_ISO_DateTime_UTC	CTD end date and time (UTC) in ISO8601 format: yyyy-mm-ddTHH:MMZ	unitless	ISO_DateTime_UTC
Start_Latitude	CTD start latitude in decimal degrees	decimal degrees	lat
Start_Longitude	CTD start longitude in decimal degrees	decimal degrees	lon
End_Latitude	CTD end latitude in decimal degrees	decimal degrees	lat
End_Longitude	CTD end longitude in decimal degrees	decimal degrees	lon
Event_ID	Geotraces event number	unitless	event
Sample_ID	Geotraces sample number	unitless	sample
Sample_Depth	Niskin trip depth. Multiple bottles were tripped to collect sample water; our samples were linked to the Niskin number having both oxygen and salinity bottle data.	meters (m)	depth
SILICATE_30_28_D_DELTA_BOTTLE_5ib7da	mean delta30Si(OH)4 relative to the NBS28 standard	per mil	Si
SD1_SILICATE_30_28_D_DELTA_BOTTLE_5ib7da	std dev delta30Si(OH)4 relative to the NBS28 standard	per mil	Si
Flag_SILICATE_30_28_D_DELTA_BOTTLE_5ib7da	quality flag for SILICATE_30_28_D_DELTA_BOTTLE_5ib7da: 1 Good = Passed documented required QC tests; 2 = Not evaluated, not available or unknown: Used for data when no QC test performed or the information on quality is not available; 3 = Questionable/suspect: Failed non-critical documented metric or subjective test(s); 4 = Bad: Failed critical documented QC test(s) or as assigned by the data provider; 9 = Missing data: Used as place holder when data are missing.	unitless	q_flag