Dataset: Palmer Station Size Fractionated Particulate Thorium

Name: Size Fractionated Particulate Thorium-234 measurements collected during the 2012-2013 Palmer Field Season
Published: 2022-08-02
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.881137.1

Spatial Extent: N:-64.815 E:-64.0405 S:-64.815 W:-64.0405

Western Antarctic Peninsula near Anvers Island

Temporal Extent: 2012-11-08 - 2013-02-11

Project:

Quantifying Processes Driving Interannual Variability in the Biological Carbon Pump in the Western Antarctic Peninsula (WAP Carbon export)

Principal Investigator:

Michael Stukel (Florida State University, FSU - EOAS)

Contact:

Michael Stukel (Florida State University, FSU - EOAS)

BCO-DMO Data Manager:

Sawyer Newman (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2022-08-02

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Size Fractionated Particulate Thorium-234 measurements collected during the 2012-2013 Palmer Field Season

Abstract:

Particle-bound Th-234 measurements and C:234Th ratios for size-fractionated particles collected during the 2012-2013 field season of the Palmer LTER program near Anvers Island in the Western Antarctic Peninsula. Particle-bound Th-234 is a useful tracer for particle scavenging and sinking processes in the ocean. Particles were sampled from 0, 10, 20, or 30 m depth and filtered through a 50-µm sieve before being concentrated onto a GF/F filter for carbon and Th-234 analyses.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2022-08-02	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.881137.1	2024-09-23

Methods & Sampling

Particulate organic carbon, nitrogen, and ²³⁴Th associated with >50-µm particles was measured at depths from the surface to 30 m at Station E near Palmer Station. Samples were collected using two different methods. For surface sampling, 20-L carboys were filled with surface seawater and gently poured through a 50-µm sieve. For samples from depth, water was pumped to the surface using a Monsoon pump and filtered through a 50-µm sieve. Volumes filtered varied depending on particle load but were typically between 50 and 100 L. Sieves were rinsed onto pre-combusted glass fiber (GF/F) filters. Filters were dried and mounted in RISO planchets. Samples were then counted in a RISO low-level beta multi-counter to determine activity of ²³⁴Th. Background counts were conducted >6 half-lives after collection. Samples were then acidified to remove CaCO₃ and analyzed in an elemental analyzer to determine particulate organic carbon and particulate nitrogen on filters. For additional details, see Stukel et al. (2022).

Data Processing Description

The data detection limits for N measurements in the data file are: 0,1.

BCO-DMO Processing

- Spaces removed from column names and replaced with underscores ("_")
- Row containing units removed from the data file
- Converted date values in the data file from %m/%d/%y %H:%M %p format to %Y-%M-%DT%H:%M format
- 'below detection' values were removed from the N column of the data file and a new field was created called N_flag; this new column indicates if a blank N value indicates if this measurement was 'below detection' limits
- Datetime in data file converted from local time at Palmer Station (UTC-3) to UTC time

Data Files

File
881137_v1_palmer_station_size_fractionated_particulate_thorium.csv (Comma Separated Values (.csv), 2.92 KB) MD5:578a2da70b34b63e405a864a21811eac Primary data file for dataset ID 881137, version 1

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Office of Polar Programs (formerly NSF PLR)	OPP-1951090
NSF Division of Ocean Sciences	OCE-1756610
NSF Office of Polar Programs (formerly NSF PLR)	OPP-1340886
NSF Office of Polar Programs (formerly NSF PLR)	OPP-1440435

Deployments

None available yet

Instruments

Elemental Analyzer

Supplied Name: Elemental analyzer

Supplied Description:

Sea water samples were acidified to remove CaCO3 and analyzed in an elemental analyzer to determine particulate organic carbon and particulate nitrogen on filters.

Instrument Type

Generic Name: Elemental Analyzer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB01/

Generic Description:

Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material.

GM multicounter

Supplied Name: Riso low-level GM beta multi-counter

Supplied Description:

Collected sediment trap samples were dried, mounted in RISO planchets and counted on a RISO low-level beta multi-counter.

Instrument Type

Generic Name: GM multicounter

Generic Description:

A gas flow multicounter (GM multicounter) is used for counting low-level beta doses. GM multicounters can be used for gas proportional counting of 32Si to 32P. For more information about GM multicounter usage see Krause et. al. 2011.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
Station	Palmer LTER station name from which sample was collected.	unitless	station
Latitude	Station Latitude in decimal degrees; a positive value indicates a Northern coordinate.	decimal degrees	lat
Longitude	Station Longitude in decimal degrees; a positive value indicates an Eastern coordinate.	decimal degrees	lon
Collection_Time	Date and time of collection in UTC. Format: %Y-%m-%dT%H:%M	unitless	DateTime
Depth	Depth at which sample was collected.	meters (m)	depth
Particulate_Th234	Thorium isotope 234Th adsorbed onto >50-um particles.	decays per minute per minute per liter (dmp/min/L)	Th234
Uncertainty	Uncertainty in thorium isotope th234Th on >50-um partcles.	decays per minute per minute per liter (dmp/min/L)	Th234
C	Particulate organic carbon (POC) in >50-um particles.	miligrams of carbon per cubic meter (mg C/m^-3)	POC
N	Particulate nitrogen in >50-um particles.	miligrams of carbon per cubic meter (mg C/m^-3)	N
N_flag	Flag column indicating rows where blank particulate nitrogen values indicate that a measurement was "below detection." The data detection limits for N in the data file are: 0,1.	unitless	q_flag

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Dataset: Palmer Station Size Fractionated Particulate Thorium