Dataset: Amazon Plume Radium-2019

Name: Radium isotope (223Ra, 224Ra, and 226Ra) measurements from CTD and underway water samples collected on R/V Endeavor cruise EN640 from June-July 2019
Published: 2021-03-24
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.846802.1

Spatial Extent: N:16.0182 E:-50.3937 S:4.87673 W:-60.0198

Temporal Extent: 2019-06-14 - 2019-07-08

Project:

Collaborative Research: Impact of the Amazon River Plume on Nitrogen Availability and Planktonic Food Web Dynamics in the Western Tropical North Atlantic (Amazon River Plume Nitrogen)

Principal Investigator:

Richard N. Peterson (Coastal Carolina University)

Co-Principal Investigator:

Joseph Montoya (Georgia Institute of Technology, GA Tech)

Ajit Subramaniam (Lamont-Doherty Earth Observatory, LDEO)

Contact:

Richard N. Peterson (Coastal Carolina University)

BCO-DMO Data Manager:

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

Version:

Version Date:

2021-03-24

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Radium isotope (223Ra, 224Ra, and 226Ra) measurements from CTD and underway water samples collected on R/V Endeavor cruise EN640 from June-July 2019

Abstract:

This dataset includes radium isotope (223Ra, 224Ra, and 226Ra) measurements from CTD and underway water samples collected on R/V Endeavor cruise EN640 from June-July 2019.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2021-03-24	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.846802.1	2021-09-07

Methods & Sampling

Water samples for radium isotope analysis were collected from both the ship's clean underway intake system ('U' designator in data) and niskin bottles attached to the CTD rosette ('C' designator in data). Salinity data were derived from the ship's clean underway intake system with SBE 21 SEACAT Thermosaliograph. Water samples were filtered through 47 mm GFF filters (unless otherwise noted), then passed slowly through 25 g (dry) acrylic fibers impregnated with MnO2 (Moore, 1976). Fibers were then washed 10x with Ra-free freshwater to remove salts and dried to a mass between 35 and 57 g for optimal humidity levels (Sun and Torgersen, 1998). Fibers were then immediately counted on a Radium Delayed Coincidence Counter (RaDeCC; Moore and Arnold, 1996) for total Ra-224 and Ra-223. Roughly 3 weeks later, fibers were counted again for supported Ra-224. Thus, excess ('XS') Ra-224 is the difference between total and supported Ra-224 measurements. Ra-226 activities were then measured on a radon emanation line as per Peterson et al. (2009).

Minimum detectable activities (dpm/100L) are calculated based on Currie (1968). Any measured values lower than the minimum detectable activity is labeled 'BD' in the dataset.

Data Processing Description

Data processing was performed in Microsoft Excel (2016).

BCO-DMO Processing:
- modified field names to conform with BCO-DMO naming conventions;
- converted date/time field to ISO8601 format.

Data Files

File
radium_2019.csv (Comma Separated Values (.csv), 49.47 KB) MD5:162ad4efd40481941181b0b71be3b3d7 Primary data file for dataset ID 846802

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1736947

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
EN640	JUN19ATL	2019-06-13	R/V Endeavor	Joseph Montoya (Chief Scientist)	data info

Instruments

Niskin bottle

Supplied Name: niskin bottles

Supplied Description:

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.

Pump - Surface Underway Ship Intake

Supplied Name: ship's clean underway

Supplied Description:

Instrument Type

Generic Name: Pump - Surface Underway Ship Intake

Acronym: Pump-Ship Intake

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

Generic Description:

The 'Pump-underway ship intake' system indicates that samples are from the ship's clean water intake pump. This is essentially a surface water sample from a source of uncontaminated near-surface (commonly 3 to 7 m) seawater that can be pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the underway supply that may also be referred to as the non-toxic supply. Ideally the data contributor has specified the depth in the ship's hull at which the pump is mounted.

Radium Delayed Coincidence Counter

Supplied Description:

Radium isotopes (224Ra and 223Ra) were analyzed with a Radium Delayed Coincidence Counter (Moore and Arnold, 1996). This system was calibrated to standard MnO2 prepared from NIST-traceable solutions of Th-232 and Ac-227 (with daughters in equilibrium).

Instrument Type

Generic Name: Radium Delayed Coincidence Counter

Acronym: RaDeCC

Generic Description:

The RaDeCC is an alpha scintillation counter that distinguishes decay events of short-lived radium daughter products based on their contrasting half-lives. This system was pioneered by Giffin et al. (1963) and adapted for radium measurements by Moore and Arnold (1996).

References:
Giffin, C., A. Kaufman, W.S. Broecker (1963). Delayed coincidence counter for the assay of actinon and thoron. J. Geophys. Res., 68, pp. 1749-1757.
Moore, W.S., R. Arnold (1996). Measurement of 223Ra and 224Ra in coastal waters using a delayed coincidence counter. J. Geophys. Res., 101 (1996), pp. 1321-1329.
Charette, Matthew A.; Dulaiova, Henrieta; Gonneea, Meagan E.; Henderson, Paul B.; Moore, Willard S.; Scholten, Jan C.; Pham, M. K. (2012). GEOTRACES radium isotopes interlaboratory comparison experiment. Limnology and Oceanography - Methods, vol 10, pg 451.

Sea-Bird SeaCAT Thermosalinograph SBE 21

Supplied Name: SBE 21 SEACAT Thermosaliograph

Supplied Description:

Instrument Type

Generic Name: Sea-Bird SeaCAT Thermosalinograph SBE 21

Acronym: SeaBird SBE-21 Seacat

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0667/

Generic Description:

A platinum-electrode conductivity sensor and a thermistor mounted in a corrosion-resistant plastic and titanium housing designed to be continuously plumbed into a vessel's pumped seawater supply. The instrument may be interfaced to a remote SBE 38 temperature sensor mounted either on the hull or in the seawater inlet. Data are both stored in internal memory and output to a serial port for external logging. Conductivity is measured in the range 0-7 S/m with an accuracy of 0.001 S/m and a resolution of 0.0001 S/m. Housing temperature is measured in the range -5-35C with an accuracy of 0.01 C and a resolution of 0.001 C. Remote temperature is measured in the range -5-35C with an accuracy of 0.001 C and a resolution of 0.0003 C. More information at http://www.seabird.com/products/spec_sheets/21data.htm.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
U_or_C	Underway (surface) or CTD sample designator	unitless	instrument
Station	Station number	unitless	station
Cast	Cast number at each station	unitless	cast
Date_Local	Local date (EST) sample collected Format: %m/%d/%y	mm/dd/yy	date
Time_Local	Local time (EST) sample collected Format: %H:%M	0:00	time
ISO_DateTime_UTC	Date and time (GMT/UTC) sample collected formatted to ISO8601 standard Format: %Y-%m-%dT%H:%MZ	YYYY-MM-DDThh:mmZ	ISO_DateTime_UTC
Latitude	Sampling latitude	decimal degrees North	lat
Longitude	Sampling longitude	decimal degrees East	lon
Depth	Water depth of sample collection	meters (m)	depth
Salinity	Salinity of ship’s seawater intake system	unitless	sal
Sample_Volume	Water sample volume	liters (L)	volume
Ra223_Activity	Radium-223 activity	dpm/100L	Ra223
Ra223_Unc	1-sigma analytical uncertainty for Ra223	dpm/100L	Ra223
XS_Ra224_Activity	Excess radium-224 activity	dpm/100L	Ra224
XS_Ra224_Unc	1-sigma analytical uncertainty for Ra224	dpm/100L	Ra224
Ra226_Activity	Radium-226 activity	dpm/100L	Ra226
Ra226_Unc	1-sigma analytical uncertainty for Ra226	dpm/100L	Ra226

Status message

Database

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Dataset: Amazon Plume Radium-2019