Dataset: th234_pump

Name: Th-234 in particulate and dissolved phases; POC/PON from R/V Thomas G. Thompson TT043, TT045, TT049, TT050 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project)
Published: 1999-01-04
Keywords: oceans

View Data: to access data, check the deployments below

Cite This Dataset

Project:

U.S. JGOFS Arabian Sea (Arabian Sea)

Program:

U.S. Joint Global Ocean Flux Study (U.S. JGOFS)

Principal Investigator:

Kenneth O. Buesseler (Woods Hole Oceanographic Institution, WHOI)

BCO-DMO Data Manager:

Cynthia L. Chandler (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

06 January 1997

Version Date:

1999-01-04

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Th-234 in particulate and dissolved phases; POC/PON from R/V Thomas G. Thompson TT043, TT045, TT049, TT050 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project)

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Description

Th-234 in particulate and dissolved phases; POC/PON

Methods & Sampling

Samples were collected using either:a) in-situ battery powered pump, the "Slurper", or b) ship’s seawater line. In general, 200 liter samples were passed sequentially through a Nitex screen (53 micron), Quartz filter (1 micron) and two thorium adsorber cartridges.

Samples were collected on legs 1 (Jan.), 2 (March), 4 (July) and 5 (August) with a few additional samples in early July (SeaSoar cruise). On each cruise: Surface samples were collected at every station (n>30); 0-100 meter composite samples were colelcted at every intermediate nd long station (n>14); and discrete depth samples were collected at every long station (n>5).

At sea analyses included: a) direct beta counting for all filters and some adsorbers samples counted 4-5 times to ensure accuracy and precision and b) direct gamma counting for adsorbers.

Post-cruise analyses included: a) CHN on all filters for POC content and b) radiochemical purification and samples plus standards counted on calibrated detectors.

Reference:
Buesseler, Ken, Lary Ball, John Andrews, Claudia Benitez-Nelson, Rebecca Belastock, Fei Chai and Yi Chao (1998). Upper ocean export of particulate organic carbon in the Arabian Sea derived from thorium-234 in Arabian Sea Expedition, Part I. Deep-Sea Research, 45(10-11): 2461-2487, U.S. JGOFS Contribution No. 411.

More Information about this dataset

Funding Sources

Funding Source	Award Number
National Science Foundation	unknown Arabian Sea NSF

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
TT043	TTN043 TN043 TTN-043	1995-01-08	R/V Thomas G. Thompson	Michael R. Roman (Chief Scientist)	data info
TT045	TTN045 TN045 TTN-045	1995-03-14	R/V Thomas G. Thompson	John F. Marra (Chief Scientist)	data info
TT049	TTN049 TN049 TTN-049	1995-07-17	R/V Thomas G. Thompson	Richard Barber (Chief Scientist)	data info
TT050	TTN050 TN050 TTN-050	1995-08-18	R/V Thomas G. Thompson	Sharon L. Smith (Chief Scientist)	data info

Instruments

Slurper Pump

Supplied Name: Ken Buesseler's Slurper pump

Supplied Description:

Ken Buesseler's Slurper pump

Instrument Type

Generic Name: Slurper Pump

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

Generic Description:

The 'Slurper' is a custom designed in situ pumping system that pumps seawater in a way that allows large-volume sampling of pre-determined depth intervals. The 'Slurper' was used during US JGOFS cruises to acquire samples for 234-Thorium and POC/PON analysis (Buesseler et al., 1988). The 'Slurper' sampling system comprised a positive displacement pump coupled to a DC motor. Pump speed and sample volume were controlled via shipboard laptop computer.

References:

Buesseler, K. O., L. Ball, J. Andrews, C. Benitez-Nelson, R. Belastock, F. Chai and Y.Chao. 1998. Upper Ocean Export of Particulate Organic Carbon in the Arabian Sea derived from Thorium-234. Deep-Sea Res. II, Arabian Sea Volume, Vol. 45, No. 10-11, 2461-2488.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
event	event number from event log		event
sta	station number from event log		sta
sta_std	Arabian Sea standard station identifier		sta_std
lat	latitude in decimal degrees		lat
lon	longitude in decimal degrees		lon
sample	surface=ship's seawater line integrated=in-situ pump (Slurper) integrated over depth range discrete=in-situ pump (Slurper) at one discrete depth		sample
depth	either surface, discrete depth or integrated depth range	meters	depth
Th234_p_gt53	particulate Th234 activity in the size fraction greater than 53 microns	dpm/liter	Th234_p_gt_53
err_p_gt53	error of particulate Th234 activity greater than 53 microns; 1 sigma		Th234_p_gt_53_err
Th234_p_1to53	particulate Th234 activity in the size fraction between 1 and 53 microns	dpm/liter	Th234_p_1to53
err_p_1to53	error of particulate Th234 activity between 1 and 53 microns; 1 sigma		Th234_p_1to53_err
Th234_d	dissolved Th234 activity	dpm/liter	Th234_d_tot
err_d	error of dissolved Th234 activity; 1 sigma		Th234_d_tot_err
POC_gt53	particulate organic carbon in the size fraction greater than 53 microns	umol/liter	POC
POC_1to53	particulate organic carbon in the size fraction between 1 and 53 microns	umol/liter	POC
PON_gt53	particulate organic nitrogen in the size fraction greater than 53 microns	umol/liter	PON_JG
PON_1to53	particulate organic nitrogen in the size fraction between 1 and 53 microns	umol/liter	PON_JG

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Dataset: th234_pump