Dataset: GP16 Be-7 Aerosol

Name: Beryllium-7 aerosol concentration from GEOTRACES Peru-Tahiti section on R/V Thomas G. Thompson cruise TN303 from October to December 2013
Published: 2016-12-29
Keywords: oceans

Cite This Dataset

Spatial Extent: N:-4.0701 E:-77.657 S:-16.0003 W:-142.9501

Project:

GEOTRACES Peru-Tahiti section: Measurement of 7Be as a Tracer of Upper Ocean Processes (EPZT Be-7)

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

Program:

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

Principal Investigator:

David C. Kadko (Florida International University, FIU)

BCO-DMO Data Manager:

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

Version:

29 December 2016

Version Date:

2016-12-29

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Beryllium-7 aerosol concentration from GEOTRACES Peru-Tahiti section on R/V Thomas G. Thompson cruise TN303 from October to December 2013

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Description

Beryllium-7 aerosol concentration from GEOTRACES Peru-Tahiti section, R/V Thompson cruise TN303.

Methods & Sampling

Aerosol samples were collected between Nov 7, 2011 and Dec 9, 2013 during the U.S. GEOTRACES EPZT cruise, R/V Thomas G. Thompson (TGT303), which took place from 25 October 2013 - 20 December 2013, Manta, Ecuador - Papeete, Tahiti, French Polynesia. Aerosol samples were obtained with a Tisch TE-5170V-BL high volume aerosol sampler, modified to collect 12 replicate samples on acid-washed (Wallace et al, 1977; Baker et al., 2006) 47 mm diameter Whatman-41 (W-41) filters, using procedures of the US GEOTRACES aerosol program (Morton et al., 2013). In order to minimize the filter blanks for our experiment, the W-41 filters were pre-cleaned before deployment using three cycles of leaching with 0.5M HCl (Optima) then rinsing with ultra-high purity water (UHP water) according to trace element protocols in a HEPA-filtered laminar flow hood (Morton et al., 2013; similar to Baker et al., 2006).

For 7Be, three of the 47 mm aerosol samples were stacked in a plastic Petri dish and counted by gamma spectroscopy. Be-7 has a readily identifiable gamma peak at 478 keV. The counting system was calibrated for all samples by preparing a commercial standard in geometry identical to the samples.

Related references:
Baker, A.R., French, M., and K.L. Linge (2006), Trends in aerosol nutrient solubility along a west-east transect of the Saharan dust plume. Geophysical Research Letters, 33, L07805, doi:10.1029/2005GL024764.

Morton, P.L., Landing, W.M., Milne, A., et al. INTERCAL: Results from the 2008 GEOTRACES aerosol intercalibration study. Limnology and Oceanography: Methods 11, 2013, 62–78.

Wallace G.T., J.R. Fletcher and R.A. Duce (1977) Filter washing, a simple means of reducing blank values and variability in trace metal environmental samples. Journal Environmental Science and Health, AI2, 493-506.

Kadko, D. and D. Olson (1996) Be-7 as a tracer of surface water subduction and mixed layer history. Deep Sea Res. 43, 89-116.

Data Processing Description

For data processing, please refer to:
Kadko, D. and D. Olson (1996) Be-7 as a tracer of surface water subduction and mixed layer history. Deep Sea Res. 43, 89-116.

BCO-DMO Processing:
- modified parameter names to conform with BCO-DMO and GEOTRACES naming conventions;
- shortened Be-7 values to 5 decimal places per communication with dataset contact;
- joined to BCO-DMO EPZT master data file;
- created ISO date/time for start and end.

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
Be7_Aerosol_joined.csv (Comma Separated Values (.csv), 3.08 KB) MD5:dd870040443f0e15c6fc975eff4db10d Primary data file for dataset ID 671814

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1232794
NSF Division of Ocean Sciences	OCE-1451120

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 TE-5170V-BL high volume aerosol sampler

Supplied Description:

Aerosol samples were obtained with a Tisch TE-5170V-BL high volume aerosol sampler, modified to collect 12 replicate samples on acid-washed 47 mm diameter Whatman-41 (W-41) filters, using procedures of the US GEOTRACES aerosol program.

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: gamma spectroscopy

Supplied Description:

For 7Be, three of the 47 mm aerosol samples were stacked in a plastic Petri dish and counted by gamma spectroscopy.

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. Added from BCO-DMO GEOTRACES EPZT master data file.	unitless	cruise_part
GEOTRC_SAMPNO	Unique GEOTRACES sample number	unitless	sample
STNNBR	Station number; added from BCO-DMO GEOTRACES EPZT master data file.	unitless	station
GEOTRC_EVENTNO	GEOTRACES event number; added from BCO-DMO GEOTRACES EPZT master data file.	unitless	event
julian_day	Julian day at start of sampling event.	unitless	julian_day
day_start	2-digit day of month at start of sampling event.	unitless	day_start
month_start	2-digit month of year at start of sampling event.	unitless	month_start
year_start	4-digit year at start of sampling event.	unitless	year_start
time_start_utc	Time (UTC) at start of sampling event. 24-hour clock; formatted as HHMM.	unitless	time_start
ISO_DateTime_UTC_start	Date and time (UTC) formatted to ISO 8601 standard. Calculated from start date and time provided. Format: YYYY-MM-DDTHH:MM:SS[.xx][+/-TZ]	unitless	ISO_DateTime_UTC
lat_start	Latitude at start of sampling event. North = Positive.	decimal degrees	lat_start
lon_start	Longitude at start of sampling event. West = Negative.	decimal degrees	lon_start
day_end	2-digit day of month at end of sampling event.	unitless	day_end
month_end	2-digit month of year at end of sampling event.	unitless	month_end
year_end	4-digit year at end of sampling event.	unitless	year_end
time_end_utc	Time (UTC) at end of sampling event. 24-hour clock; formatted as HHMM.	unitless	no_bcodmo_term
ISO_DateTime_UTC_end	Date and time (UTC) formatted to ISO 8601 standard. Calculated from end date and time provided. Format: YYYY-MM-DDTHH:MM:SS[.xx][+/-TZ]	unitless	ISO_DateTime_UTC
lat_end	Latitude at end of sampling event. North = Positive.	decimal degrees	lat_end
lon_end	Longitude at end of sampling event. West = Negative.	decimal degrees	lon_end
air_vol	Air volume sampled	cubic meter (m^3)	sample_volume
Be_7_AER_CONC_TISCH	Beryllium-7 (Be-7) aerosol concentration	becquerels per cubic meter (bq/m3)	metal_conc_air
Be_7_AER_CONC_TISCH_ERR	Error (+/-) associated with Be-7 measurement	becquerels per cubic meter (bq/m3)	metal_conc_air

Status message

Database

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Dataset: GP16 Be-7 Aerosol