Dataset: GT10-11 - Dissolved Po Pb
Deployment: KN204-01

Dissolved 210Po and 210Pb from US GEOTRACES North Atlantic KN199-04 and KN204-01

Principal Investigator:

Thomas M. Church (University of Delaware)

Co-Principal Investigator:

Mark Baskaran (Wayne State University, WSU)

Dr Sylvain Rigaud (EPOC (Environnements et Paleoenvironnements Oceaniques et Continentaux), UMR Universite Bordeaux - CNRS, EPOC UMR CNRS)

Gillian Stewart (Queens College, CUNY QC)

BCO-DMO Data Manager:

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

Danie Kinkade (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

U.S. GEOTRACES North Atlantic Transect (GA03) (U.S. GEOTRACES NAT)

Current State:

Final no updates expected

Deployment Synonyms:

GA03, GT11, KN204-01A, KN204-01B, USGT-NAT-2011, USGNAZT, GNAT, 316N20111106, KN204-1

Version Date:

2013-04-19

Data URL:

https://osprey.bco-dmo.org/dataset-deployment/455938/data

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Description

Free access for all member of the US GEOTRACES program, only for the first two years, then open access.

DMO Note: the November 5, 2013 version replaces previous data file dated April 17, 2013.

Methods & Sampling

Dataset acquisition description

Sampling and Analytical Methodology for Dissolved NAST 210Po and 210Po Sample

Currently, the recommended assay of both dissolved and particulate sea water samples are outlined in the GEOTRACES procedures manual at:
http://www.obs-vlfr.fr/GEOTRACES/science/intercalibration/222-sampling-and-sample-handling-protocols-for-geotraces-cruises

Specific methods based on this cruise follow.

The dissolved samples were drawn onboard from 30 liter Niskin bottles deployed on the rosette and at the designated depths. The samples were filtered (0.45 micron) seawater using Acropac capsules with Supor membranes, and acidified (pH2 with Optima HCl). The twenty liter cubitainers were rinsed, filled and sealed dark at sea and transferred to cold storage after shipping and before analysis ashore. The samples were spiked with a well-calibrated 209Po tracer solution (T1/2 =102 y), together with a stable lead carrier added to monitor the losses of Po and Pb during sample processing. For the dissolved samples, Po and Pb were pre-concentrated from large volumes of seawater via co-precipitation with Fe(OH)3 (Thomson and Turekian 1976; Nozaki 1986). The Po nuclides are then plated by spontaneous deposition onto a silver disc (Flynn 1968). Silver discs, 1-2 cm in diameter, were be obtained with greater than 99.99% purity from A.F. Murphy Die and Machine Co, Inc. USA. They were first cleaned with a commercial silver polish and then using water and ethanol. One side of the disc was covered by rubber cement, so that Po was plated on only one side. The Po activities were measured after deposition by alpha spectrometry (Ortec Inc, Alpha Quad; Canberra Inc., Alpha Analyst). Any remaining 209Po and 210Po in solution was removed by using anion exchange resin AG-1X8 (Sarin et al. 1992). After separation, the final eluate containing the 210Pb was re-spiked with 209Po and stored for greater than 6 months to allow in-growth of 210Po from 210Pb. At that time, the 210Pb activity of the sample was determined by replating the eluate on a new silver disc and measuring the in-growth of 210Po. The determination of the initial activities of 210Po and 210Pb in the sample at the time of collection accounted for decay and ingrowth between the time of collection and processing, with corrections for chemical recoveries (Rigaud, et al., in revision). The error analysis accounts for the relative uncertainty for each parameter considered in the calculation of final 210Po and 210Pb activities. For the cruise, the method allows estimating 210Pb activity with a relative uncertainty of about 7%. However for 210Po activities, the final relative uncertainty is more variable and depends on the 210Po/210Pb activity ratio in the initial sample and the time elapsed between sampling and sample processing. For samples from this cruise, the 210Po uncertainty is not better than 6%.

References

Fleer, A. P., and M. P. Bacon. 1984. Determination of 210Pb and 210Po in seawater and marine particulate matter. Nucl. Instrum. Methods Phys. Res. 223: 243-249.

Flynn, W. W. 1968. The determination of low levels of polonium-210 in environmental materials. Anal. Chim. Acta 43: 221-227.

Nozaki, Y. 1986. 226Ra-222Rn-210Pb systematics in seawater near the bottom of the ocean. Earth Planet. . Earth Planet. Sci. Lett. 32: 304-312.

Sarin, M. M., R. Bhushan, R. Rengarajan, and D. N. Yadav. 1992. The simultaneous determination of 238U series nuclides in seawater: results from the Arabian Sea and Bay of Bengal. Indian J. Mar. Sci. 21: 121-127.

Thomson, J., and K. K. Turekian. 1976. 210Po and 210Pb distributions in ocean water profiles from the Eastern South Pacific. Earth Planet. Sci. Lett. 32: 297-303.

Data Processing Description

Dataset Processing Description

Also see section above.

Raw data were corrected for ingrowth, decay, isotope recoveries, detector background and blanks.

Quality Code	Definition	How to Use it
1	Sampled but not yet received.	A sample for this measurement has been drawn but the results have not yet been received. This is an internal sample inventory code. It should not be reported. See code 5 for samples that are lost.
2	No problems noted.	Not necessary (default).
3	Questionable measurement.	Does not fit cast profile, adjacent casts or other criteria. No problems were noted by the analyst.
4	Bad measurement.	Does not fit cast profile, adjacent casts or other criteria. Analytical or sampling problems are likely.
5	Sample not reported.	The sample (or analysis) was lost. A value could not be reported.
6	Mean of replicate measurements.	The value reported is a mean of replicate measurements.
7	Manual (chromatographic) peak measurement.	A normally machine-generated peak measurement was derived manually.
8	Irregular digital chromatographic peak integration.	A machine-generated peak measurement was found to be abnormal.
9	Sample not drawn from this bottle.	No sample was drawn

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.

Additional BCO-DMO Processing Notes:

The submitted event number was 2009 for samples 5624 - 5635, while in the master file, those samples are correspond to event 2162. These values were changed to agree with master file.

Missing data were replaced wtih 'nd'.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0961653	NSF Division of Ocean Sciences

Instruments

CTD Sea-Bird SBE 911plus

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird SBE 911plus

Acronym: CTD SBE 911plus

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0058/

Generic Description:

The Sea-Bird SBE 911 plus is a type of CTD instrument package for continuous measurement of conductivity, temperature and pressure. The SBE 911 plus includes the SBE 9plus Underwater Unit and the SBE 11plus Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 plus and SBE 11 plus is called a SBE 911 plus. The SBE 9 plus uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 plus and SBE 4). The SBE 9 plus CTD can be configured with up to eight auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). more information from Sea-Bird Electronics

GO-FLO Bottle

Supplied Description:

Instrument Type

Generic Name: GO-FLO Bottle

Acronym: GO-FLO

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

Generic Description:

GO-FLO bottle cast used to collect water samples for pigment, nutrient, plankton, etc. The GO-FLO sampling bottle is specially designed to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths.

Niskin bottle

Supplied Description:

30 liter bottles

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 e.g. KN199-04 = R/V Knorr cruise number 199-04	dimensionless	cruise_id
cruise_name	project designated cruise name	dimensionless	cruise_name
EXPOCODE	project cruise id code	dimensionless	cruise_name
station_GEOTRC	GEOTRACES station number	dimensionless	station
depth_GEOTRC_CTD	Observation/sample depth in meters; calculated from CTD pressure. Values were added from the intermediate US GEOTRACES master file (see Processing Description); same as depth provided by PI.	meters	depth
event_GEOTRC	Unique identifying number for US GEOTRACES sampling events; ranges from 2001 to 2225 for KN199-04 events and from 3001 to 3282 for KN204-01 events. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	dimensionless	event
cast_GEOTRC	Cast identifier numbered consecutively within a station. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	dimensionless	cast
sample_GEOTRC	Unique identifying number for US GEOTRACES samples	dimensionless	sample
sample_bottle_GEOTRC	Unique identification numbers given to samples taken from bottles; ranges from 1 to 24; often used synonymously with bottle number. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	dimensionless	bot_Nis
bottle_GEOTRC	Alphanumeric characters identifying bottle type (e.g. NIS representing Niskin and GF representing GOFLO) and position on a CTD rosette. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	dimensionless	bottle
date	sampling date	YYYYmmDD	date
bottle_num_flag	quality flag	dimensionless	flag
time	sampling time	HHMM	time
lat	latitude; North is positive	decimal degrees	lat
lon	longitude; East is positive	decimal degrees	lon
Po_210	dissolved Polonium-210 concentration	dpm/100 kilgrams	trace_metal_conc
Po_210_flag	quality flag	dimensionless	flag
Pb_210	dissolved Lead-210 concentration	dpm/100 kilgrams	trace_metal_conc
Pb_210_flag	quality flag	dimensionless	flag
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). This standard is based on ISO 8601:2004(E) and takes on the following form: 2009-08-30T14:05:00[.xx]Z (UTC time)	YYYY-mm-DDTHH:MM:SS.SSZ	ISO_DateTime_UTC
Pb_210_sd	Standard deviation reported for the concentration of Lead-210.	dpm/100 kiligrams	trace_metal_sd
Po_210_sd	Standard deviation reported for the concentration of Polonium-210.	dpm/100 kiligrams	trace_metal_sd

Database

Contribute Data

Dataset: GT10-11 - Dissolved Po Pb
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GT10-11 - Dissolved Po PbDeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: GT10-11 - Dissolved Po Pb
Deployment: KN204-01