Dataset: GT11 - Be-7 Aerosol
Deployment: KN204-01

Beryllium-7 in aerosol

Principal Investigator:

David C. Kadko (Florida International University, FIU)

BCO-DMO Data Manager:

Shannon Rauch (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

Version:

22 December 2016

Deployment Synonyms:

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

Version Date:

2016-12-22

Data URL:

https://www.bco-dmo.org/dataset-deployment/671111/data

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Description

Beryllium-7 in aerosol samples collected on the US GEOTRACES North Atlantic Transect (NAT) cruise, KN204-01.

Methods & Sampling

Dataset acquisition description

Aerosol samples were collected between Nov 7, 2011 and Dec 9, 2011 during the R/V Knorr KN204-01 North Atlantic GEOTRACES expedition. 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) 47mm 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 47mm 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.

Data Processing Description

Dataset 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 naming conventions;
- added cruise_part;
- added ISO_DateTime columns using the original dates/times provided;
- joined additional columns from master file (see below).

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 name 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.

More information about this dataset deployment

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 47mm diameter Whatman-41 (W-41) filters, using procedures of the US GEOTRACES aerosol program.

Instrument Type

Generic Name: Aerosol Sampler

Acronym: 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 47mm 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

Supplied Name	Supplied description	Supplied Units	Standard Name
day_end	2-digit day of month at end of sampling event.	unitless	day_end
day_start	2-digit day of month at start of sampling event.	unitless	day_start
month_end	2-digit month of year at end of sampling event.	unitless	month_end
month_start	2-digit month of year at start of sampling event.	unitless	month_start
year_end	4-digit year at end of sampling event.	unitless	year_end
year_start	4-digit year at start of sampling event.	unitless	year_start
Be_7_AER_CONC_TISCH_ERR	Error (+/-) associated with Be-7 measurement	becquerels per cubic meter (bq/m3)	metal_conc_air
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
air_vol	Air volume sampled	cubic meter (m^3)	sample_volume
Be_7_AER_CONC_TISCH	Be-7 in aerosols	becquerels per cubic meter (bq/m3)	metal_conc_air
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
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
station_GEOTRC	GEOTRACES station number; ranges from 1 through 12 for KN199-04 and 1 through 24 for KN204-01. Stations 7 and 9 were skipped on KN204-01. Some GeoFish stations are denoted as X_to_Y indicating the tow occurred between stations X and Y. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	unitless	sta
julian_day	Julian day at start of sampling event.	unitless	julian_day
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
cruise_id	Official cruise identifier e.g. KN199-04 = R/V Knorr cruise number 199-04.	unitless	cruise_id
cruise_part	Part of cruise. For KN204-01: A = 11/6/2011 to 11/18/2011 (Woods Hole to Bermuda); B = 11/19/2011 to 12/11/2011 (Bermuda to Praia, Cabo Verde)	unitless	cruise_part
time_end_utc	Time (UTC) at end of sampling event. 24-hour clock; formatted as HHMM.	unitless	no_bcodmo_term
time_start_utc	Time (UTC) at start of sampling event. 24-hour clock; formatted as HHMM.	unitless	time_start
sample_GEOTRC	Unique identifying number for US GEOTRACES samples; ranges from 5033 to 6078 for KN199-04 and from 6112 to 8148 for KN204-01.	unitless	sample
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).	unitless	event

Database

Contribute Data

Dataset: GT11 - Be-7 Aerosol
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GT11 - Be-7 AerosolDeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: GT11 - Be-7 Aerosol
Deployment: KN204-01