Dataset: GP16 Lead-210 Aerosols

Name: Aerosols analyzed for Pb-210 collected on R/V Thomas G. Thompson cruise TN303 in the Eastern Tropical Pacific from October to December 2013 (U.S. GEOTRACES EPZT project)
Published: 2017-01-09
Keywords: oceans

Cite This Dataset

Spatial Extent: N:-4.0701 E:-79.1952 S:-16.0003 W:-140.0014

Project:

GEOTRACES - 210Po and 210Pb distribution at Eastern Pacific Interface Regimes (GEOTRACES EPZT Po Pb)

U.S. GEOTRACES East Pacific Zonal Transect (GP16) (U.S. GEOTRACES EPZT)

Program:

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

Principal Investigator:

Mark Baskaran (Wayne State University, WSU)

BCO-DMO Data Manager:

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

Version:

19 January 2017

Version Date:

2017-01-09

Restricted:

Release Date:

2017-08-18

Validated:

Yes

Current State:

Final no updates expected

Aerosols analyzed for Pb-210 collected on R/V Thomas G. Thompson cruise TN303 in the Eastern Tropical Pacific from October to December 2013 (U.S. GEOTRACES EPZT project)

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Description

Aerosols collected during the GEOTRACES EPZT cruise (TN303), analyzed for Pb-210

Methods & Sampling

During the GEOTRACES GP16 (EPZT) cruise, aerosol samples (for bulk aerosols using a Tisch Environmental TSP TE-5170V-BL, 47mm Whatman 41 filters and size-fractionated aerosols using a Tisch TE-235 5-stage slotted impactor with Whatman 41 slotted substrates) by the Florida State University group (FSU) aboard the RV Thompson. Aerosol samples were frozen onboard and sent to FSU. The filter were cut into strips and sent to Wayne State University for radiochemical processing. The filter strips were placed in a digestion vessel and 5 ml each of concentrated HCl, concentrated HNO3 and HF were added. To the mixture, precisely weighed 209Po equivalent to 1 dpm was added. The mixture was digested at 100 degrees C for about 24-hours in a furnace. After the digestion was complete, the solution was transferred into a 100 ml pre-cleaned Teflon beaker and evaporated. To the residue, 5.0 ml conc. HCl was added and dried. This process was repeated one more time and finally 5.0 ml 6M HCl was added to the residue. To this solution, 45.0 ml of deionized water was added and the solution was quantitatively transferred into a 100 ml low density polyethylene bottle and stored for ~ 1 yr. After the time elapsed, Po plating was conducted as described in Baskaran et al. (2013). The planchet was assayed in an alpha spectrometer. Appropriate decay corrections, including the decay of 210Pb from the time of sample collection to plating, were applied and the final activity of 210Pb was calculated (Baskaran et al., 2013).

Data Processing Description

After deployment blank subtraction, negative amounts were used to represent detection limits. Equations used can be found in Baskaran et al. (2013).

BCO-DMO Processing:
-modified parameter names to conform with BCO-DMO and GEOTRACES naming conventions;
-replaced blanks (missing data) with nd.

Additional GEOTRACES Processing:
As was done for the GEOTRACES-NAT data, 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:

cruise_id, EXPOCODE,SECT_ID, STNNBR, CASTNO, GEOTRC_EVENTNO, GEOTRC_SAMPNO, GEOTRC_INSTR, SAMPNO, GF_NO, BTLNBR, BTLNBR_FLAG_W, DATE_START_EVENT, TIME_START_EVENT, ISO_DATETIME_UTC_START_EVENT, EVENT_LAT, EVENT_LON, DEPTH_MIN, DEPTH_MAX, BTL_DATE, BTL_TIME, BTL_ISO_DATETIME_UTC, BTL_LAT, BTL_LON, ODF_CTDPRS, SMDEPTH, FMDEPTH, BTMDEPTH, CTDPRS, CTDDEPTH.

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 and ODF_Bottle datasets. Non-bottle parameters, including those from GeoFish tows, Aerosol sampling, and McLane Pumps, were taken from the TN303 Event Log (version 30 Oct 2014). Where applicable, pump information was taken from the PUMP_Nuts_Sals dataset.

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.

Data Files

File
Pb210_Aerosol_joined.csv (Comma Separated Values (.csv), 5.26 KB) MD5:a4fba3306852c80c31672adf3a48a4f6 Primary data file for dataset ID 675403

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1237059

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
TN303	GP16 GEOTRACES EPZT GEOTRACES East Pacific Zonal Transect (EPZT) GT13 325020131025	2013-10-25	R/V Thomas G. Thompson	James W. Moffett (Chief Scientist) Gregory A. Cutter (Co-Chief Scientist) Christopher R. German (Co-Chief Scientist)	data info

Instruments

Aerosol Sampler

Supplied Name: Tisch Environmental TSP TE-5170V-BL

Supplied Description:

Aerosol samples (for bulk aerosols using a Tisch Environmental TSP TE-5170V-BL, 47mm Whatman 41 filters and size-fractionated aerosols using a Tisch TE-235 5-stage slotted impactor with Whatman 41 slotted substrates) by the Florida State University group (FSU).

Refer to: https://tisch-env.com/wp-content/uploads/2015/07/TE-5170V-BL-Manual.pdf

Instrument Type

Generic Name: Aerosol Sampler

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/13/

Generic Description:

A device that collects a sample of aerosol (dry particles or liquid droplets) from the atmosphere.

Spectrometer

Supplied Name: Alpha Spectrometer

Supplied Description:

The planchet was assayed in an alpha spectrometer.

Instrument Type

Generic Name: Spectrometer

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0460/

Generic Description:

A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	Cruise identification	unitless	cruise_id
SECT_ID	Cruise section identifier; EPZT = GEOTRACES East Pacific Zonal Transect.	unitless	cruise_part
GEOTRC_INSTR	Sampling instrument; added from BCO-DMO EPZT master data file.	unitless	instrument
GEOTRC_EVENTNO	GEOTRACES event number	unitless	event
GEOTRC_SAMPNO	Unique GEOTRACES sample number	unitless	sample
deployment	Deployment identifier	unitless	no_bcodmo_term
STNNBR	Station number; added from BCO-DMO EPZT master data file.	unitless	station
sampler_type	Aerosol sampler type	unitless	instrument
stage	The Tisch Ambient Eight-Stage Cascade Impactor (Impactor) is a high sample-rate, multiple orifice and multiple stage Inertial Impactor. A Cascade Impactor is a multi-stage impaction device used to separate airborne particles into aerodynamic size classes. Ambient air enters the circular inlet of the Pre-Impactor Size Selective Inlet (High Capacity Pre-Separator) and cascades through the succeeding orifice stages with successively higher orifice velocities from Stage #0 to Stage #7.	unitless	no_bcodmo_term
impactor_strip	Impactor strip identifier. The Tisch Ambient Eight-Stage Cascade Impactor (Impactor) is a high sample-rate, multiple orifice and multiple stage Inertial Impactor. A Cascade Impactor is a multi-stage impaction device used to separate airborne particles into aerodynamic size classes. Ambient air enters the circular inlet of the Pre-Impactor Size Selective Inlet (High Capacity Pre-Separator) and cascades through the succeeding orifice stages with successively higher orifice velocities from Stage #0 to Stage #7.	unitless	no_bcodmo_term
julian_day	Sampling start Julian day	unitless	julian_day
day_start	Sampling start day	unitless	day
month_start	Sampling start month	unitless	month
year_start	Sampling start year	unitless	year_start
lat_start	Sampling start Latitude; North = positive values.	decimal degrees	lat_start
lon_start	Sampling start Longitude; East = positive values.	decimal degrees	lon_start
day_end	Sampling end day	unitless	day
month_end	Sampling end month	unitless	month
year_end	Sampling end year	unitless	year_end
lat_end	Sampling end Latitude; North = positive values.	decimal degrees	lat_end
lon_end	Sampling end Longitude; East = positive values.	decimal degrees	lon_end
run_time_hrs	Run time of the sampler	hours	duration
air_volume	Total volume of air sampled	cubic meters	sample_volume
Pb_210_AEROSOL_CONC	Pb-210 concentration	decays per minute/1000 cubic meters	metal_conc_air
Pb_210_AEROSOL_CONC_SD	Standard deviation of Pb-210 concentration	decays per minute/1000 cubic meters	metal_conc_air
Pb_210_AEROSOL_CONC_FLAG	Quality flag for Pb-210 concentration	unitless	q_flag
ISO_DATETIME_UTC_START_EVENT	Date and time, formatted to the ISO 8601 standard, at the start of the sampling event, according to the event log. Format: YYYY-MM-DDTHH:MM:SS[.xx]Z	unitless	ISO_DateTime_UTC

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Dataset: GP16 Lead-210 Aerosols