Dataset: GT10-11 - delta 30Si
Deployment: KN204-01

Profiles of stable isotopes of silicon (Si) in silicic acid (Si(OH)4) from GT10 and GT11 cruises.

Principal Investigator:

Mark A. Brzezinski (University of California-Santa Barbara, UCSB-MSI)

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:

04 Nov 2013

Deployment Synonyms:

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

Version Date:

2013-11-04

Data URL:

https://www.bco-dmo.org/dataset-deployment/456171/data

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Description

Profiles of stable isotopes of silicon in silicic acid (delta 30Si) collected at stations during the GT10 (KN199-04) and GT11 (KN204-01) U.S. GEOTRACES North Atlantic Transect cruises.

Methods & Sampling

Dataset acquisition description

Refer to the Si Natural Abundance Protocol document (PDF) for methodology.

Briefly: Water samples were collected with a conventional CTD and rosette as Si isotopes are not contamination prone. Water samples were filtered through a polyethersulfone filter cartridge directly from each sampling bottle using silicon tubing and stored in either high density polyethylene or polypropylene bottles that were precleaned by an overnight soak in 10% ACS grade HCl and rinsed with high purity deionized distilled water (> 18 M-Ohm - cm) and stored at room temperature.

Analytical methodology followed Brzezinski et al. (2006).

Data Processing Description

Dataset Processing Description

Occasionally samples are too small to obtain a value or are lost due to problems in sample preparation. These are flagged as NEED TO DECIDE.

BCO-DMO Processing Notes:
- Modified parameter names to conform with BCO-DMO naming conventions.
- Separated original date-time field into date_gmt and time_gmt.
- Added column for the official cruise_id.
- 17-Dec-2018: removed embargo on dataset.

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.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1129227	NSF Division of Ocean Sciences

Instruments

Niskin bottle

Supplied Description:

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.	text	cruise_id
cruise_name	GEOTRACES cruise identifier.	text	cruise_name
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. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Station', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.	dimensionless	station
cast_GEOTRC	Cast identifier numbered consecutively within a station. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	dimensionless	cast
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. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Event #', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.	dimensionless	event
depth_w	Bottom depth (depth of the water), in meters.	meters	depth_w
lat	Latitude. South is negative.	decimal degrees	lat
lon	Longitude. West is negative.	decimal degrees	lon
date_gmt	Date (GMT) when the sampling event occurred; 4-digit year, 2-digit month, 2-digit day.	unitless	date_gmt
time_gmt	Time (GMT) when the sampling event occurred, in hours, minutes, and decimal minutes. in the format HHmm.xx	unitless	time_gmt
event_ISO_DateTime_UTC	Date and time (UTC) when the sampling event occurred formatted to the ISO 8601 standard, where T represents the start of the time string. in the format YYYY-mm-ddTHH:MM:SS.xx	unitless	ISO_DateTime_UTC
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. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Samp#', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.	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	bot
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).	meters	depth
d30Si_mean	Mean delta30Si(OH)4 relative to the NBS28 standard (NIST RM 8546).	per mil (0/00)	no_bcodmo_term
d30Si_mean_sd	Standard deviation of d30Si_mean; standard deviation of delta30Si(OH)4 relative to the NBS28 standard (NIST RM 8546).	per mil (0/00)	std_dev
num_reps	Number of values for mean and standard deviation of delta30Si(OH)4.	dimensionless	num_reps
status_comment	Comment on the status of the data.	text	comment
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-dd'T'HH:mm:ss.SS'Z'	ISO_DateTime_UTC

Database

Contribute Data

Dataset: GT10-11 - delta 30Si
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GT10-11 - delta 30SiDeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: GT10-11 - delta 30Si
Deployment: KN204-01