Dataset: GT10-11 - delta_13C
Deployment: KN199-04

delta 13C measurement of dissolved inorganic carbon (DIC) from GT10 and GT11 cruises.

Principal Investigator:

Paul Quay (University of Washington, UW)

Contact:

Johnny Stutsman (University of Washington, UW)

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:

17 June 2014

Deployment Synonyms:

GA03, GT10, USGT-NAT-2010, KN199-4, GNAT, U.S. GEOTRACES NAZT Leg 1, knorr199-4/5, Section Cruise (GA03), 316N20101015

Version Date:

2014-06-17

Data URL:

https://www.bco-dmo.org/dataset-deployment/455895/data

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Description

delta 13C measurements made on dissolved inorganic carbon (DIC) samples collected at stations during the GT10 and GT11 (KN199-04 and KN204-01) cruises as part of the U.S. GEOTRACES North Atlantic Transect project.

Version History:
17 June 2014 (current version) = data updated/corrections made; several bottle numbers, cast numbers, and depth values that were previously erroneous have been corrected;
04 April 2013 = original data submitted.

Methods & Sampling

Dataset acquisition description

Shipboard Sample Collection Methods
Samples are collected in pre-washed and baked 250 ml ground glass stoppered bottles that were poisoned with 100µl of a saturated HgCl2 solution. The stored sealed samples were returned to the Stable Isotope Laboratory at the University of Washington for extraction and measurement.

Laboratory Methods
CO2 is extracted from the DIC seawater sample using a modification of the helium stripping technique described in Quay et al (1992). The del13C is measured on a Thermo Delta Plus XL mass spectrometer.

Data Processing Description

Dataset Processing Description

Data Processing
Surface samples collected at stations through sample clean seawater feed have no cast and sample numbers.
Quality flags here include:
2 = good data;
3 = questionable data;
9 = no data.

BCO-DMO Processing Notes:
- Modified parameter names to conform with BCO-DMO naming conventions.
- Separated original date field into month, day, and year.
- Replaced blanks with 'nd'.
- Added 'cruise_id' based on the 'cruise_name' provided.
- lat_nom and lon_nom were added from station waypoints provided by the cruise Chief Scientists.

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-0926213	NSF Division of Ocean Sciences
OCE-1137455	NSF Division of Ocean Sciences

Instruments

Isotope-ratio Mass Spectrometer

Supplied Description:

The del13C is measured on a Thermo Delta Plus XL mass spectrometer.

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).

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	GEOTRACES cruise identifier.	dimensionless	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. 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
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
cast_GEOTRC	Cast identifier, numbered consecutively within a station. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Cast', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.	dimensionless	cast
sample_bottle_GEOTRC	Unique identification numbers given to samples taken from bottles; rangies from 1 to 24; often used synonymously with bottle number. PI-supplied values were identical to those in the intermediate US GEOTRACES master file. Originally submitted as 'Sample', this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions.	dimensionless	bot_Nis
lat	Latitude ranging from 0 to +/- 180.	decimal degrees	lat
lon	Longitude ranging from 0 to +/- 180. Negative values = West.	decimal degrees	lon
month	2-digit month of year (UTC). in the format mm (01 to 12)	unitless	month_utc
day	2-digit day of month (UTC). in the format dd (01 to 31)	unitless	day_gmt
year	4-digit year (UTC). in the format YYYY	unitless	year
delta13C	A measure of the ratio of stable isotopes 13C:12C, reported in parts per thousand (per mil, o/oo) reported vs PDB.	per mil	delta13C
delta13C_flag	Quality flag for delta13C. 2 = good data 3 = questionable data 9 = no data	dimensionless	q_flag
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
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. Values were added from the intermediate US GEOTRACES master file (see Processing Description).	dimensionless	sample
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
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
lat_nom	Nominal latitude of station. BCO-DMO added from station waypoints provided by Chief Sci.	decimal degrees	lat_n
lon_nom	Nominal longitude of station. BCO-DMO added from station waypoints provided by Chief Sci.	decimal degrees	lon_n

Database

Contribute Data

Dataset: GT10-11 - delta_13C
Deployment: KN199-04

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GT10-11 - delta_13CDeployment: KN199-04

Dataset acquisition description

Dataset Processing Description

Dataset: GT10-11 - delta_13C
Deployment: KN199-04