Dataset: GT10 - POC_PON

Name: Particulate organic carbon (POC) and nitrogen (PON) along US GEOTRACES North Atlantic Transect from the R/V Knorr KN199-04 cruise in the subtropical N. Atlantic from 2010 (U.S. GEOTRACES NAT project)
Published: 2013-01-10
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.3851.1

Spatial Extent: N:38.3296 E:-9.6604 S:17.3581 W:-24.4962

Temporal Extent: 2010-10-17 - 2010-11-02

Project:

U.S. GEOTRACES North Atlantic Transect (GA03) (U.S. GEOTRACES NAT)

Program:

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

Principal Investigator:

Joaquin Chaves (National Aeronautics and Space Administration, NASA)

Co-Principal Investigator:

Charles McClain (National Aeronautics and Space Administration, NASA)

BCO-DMO Data Manager:

Danie Kinkade (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2013-01-10

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Particulate organic carbon (POC) and nitrogen (PON) along US GEOTRACES North Atlantic Transect from the R/V Knorr KN199-04 cruise in the subtropical N. Atlantic from 2010 (U.S. GEOTRACES NAT project)

Abstract:

Particulate organic carbon (POC) and nitrogen (PON) along US GEOTRACES North Atlantic Transect from the R/V Knorr KN199-04 cruise in the subtropical N. Atlantic from 2010.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2013-01-10	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.3851.1	2020-05-01

Description

Particulate organic carbon (POC) and nitrogen (PON) from surface samples collected on Whatman, 2.5cm glass fiber filters (GFF). Samples were collected during Geotraces 2010 (kn199-04).

Additional Dataset Information extracted from original file header:

/begin_header
/investigators=Joaquin_Chaves    Charles_McClain
/affiliations=NASA
/contact=joaquin.chaves@nasa.gov
/experiment=GEOTRACES
/cruise=kn199-04
/station=NA
/data_file_name=kn199-04_POC_N_BCODMO.csv
/documents=POC_Pkn_Elmer_2400.pdf
/calibration_files=kn199-04_POC_run.pdf
/data_type=bottle
/data_status=final
/start_date=20101017
/end_date=20101102
/start_time=11:20:00[GMT]
/end_time=17:10:00[GMT]
/north_latitude=38.3296[DEG]
/south_latitude=17.3581[DEG]
/east_longitude=-9.6604[DEG]
/west_longitude=-24.4962[DEG]
/water_depth=-999
/measurement_depth=-999
/secchi_depth=-999
/wind_speed=-999
/cloud_percent=-999
/wave_height=-999
!
!The field "replicates" indicates how many replicate samples were
!averaged to produce the reported value

-----

NOTE: The following header line was incorrect and subsequently corrected by BCO-DMO
! sample_no==-999 were collected with NASA's surface peristaltic pump
----

! quality = 1 good; 2 = medium; 3 = suspect
!
/missing=-999
/delimiter=comma

Methods & Sampling

Sampling Excerpt from associated file: Determination of Carbon and Nitrogen collected on Whatman glass fiber filters (GFF)

Water samples are filtered through 2.5 cm pre-combusted Whatman GFF filters using an all-glass filtering funnel. Once enough material has been accumulated on the filter the samples are stored in Nalgene 1.8 mL cryovials at -80°C until analysis. For shipping, samples are stored in liquid nitrogen dry-shippers. Prior to analysis samples are thawed and dried overnight at 65°C inside the uncapped cryovials. Dry samples in the uncapped vials are transferred overnight to a desiccator saturated with HCl fumes to remove particulate inorganic carbon present in the sample. The air in the desiccator is kept saturated by leaving concentrated HCl in an open container in the lower compartment of the desiccator. Acid–treated samples are transferred back to a 65°C oven overnight, after which can be stored capped in cryovials for extended periods prior to analysis in elemental analyzer.

For analysis the samples are wrapped in tin foil discs (PE N241-1363) and pelletized on a Parr Pellet press.

The samples are analyzed in the Perkin Elmer CHNS/O Analyzer 2400 Series II. The manufacturer’s data management software for the elemental analyzer is set up so that the analysis report includes the zero read (ZR), and the carbon and nitrogen signals (CS, NS) from the instrument for each analyzed sample.

For complete analysis and processing details, see the Supplemental Document: Determination of Carbon and Nitrogen collected on Whatman glass fiber filters (GFF) (POC_Pkn_Elmer_2400.pdf).

Data Processing Description

Data are averages of samples replicates, the number of which is indicated as a data column. Standard deviation of replicates is included as a data column as well. Data has been visually QA/QC. Samples runs results are compared against NIST 'Buffalo River sediment' reference material and Perkin Elmer Acetanylide runs.

Data processing and calibration is performed in Matlab using a script that generates a data report that includes the C and N content in mg for each filter replicate sample. For details on processing and calibration, please see the accompanying Supplemental Documents (kn199-04_POC_data_process.pdf)

BCO-DMO Processing Notes:
- Parameter header names were renamed to BCO-DMO convention
- Edited blank data fields and data reported as -999 to 'nd'
- Edited time to remove colons and drop unused seconds
- Edited precision of lat/lon to four decimals.
- Edited precision of POC, PON, PON_sd and POC_sd to one decimal.
- Removed the following header information from the file. Where necessary the information was incorporated into BCO-DMO metadata fields and retained entirely as 'additional information':

NOTE: The value -999 in the original file "sample" parameter, was used represent samples taken with a surface pump. This value was set by the PI, to indicate NASA's pump. However, correspondence with the PI on 2013.01.12, has corrected header note regarding sample numbers.

Therefore, the comment retained in the header has been edited to the following text, as per the PI, and sample numbers of -999 have been changed to 'nd' and additional metadata in the sample number parameter indicates that samples wtih GEOTRACES numbers had corresponding pigment samples taken, those with 'nd' did not:

# Samples from station 1 with 0 depth were collected with WHOI's GEOTRACES pump
# Sample numbers for stations > 1 with depth = 0 were collected with NASA's
# surface peristaltic pump

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.

Data Files

File
POC_PON_GT10_joined.csv (Comma Separated Values (.csv), 1.19 KB) MD5:c6777dc0b46fd56404cbab2ccd424c03 Primary data file for dataset ID 3851

Supplemental Files

File
Determination of Carbon and Nitrogen collected on Whatman glass fiber filters (GFF) filename: POC_Pkn_Elmer_2400.pdf (Portable Document Format (.pdf), 284.54 KB) MD5:f3209fcecc2025842b5478c6d99b0701 Determination of Carbon and Nitrogen collected on Whatman glass fiber filters (GFF)
Processing and calibration information for the GT10 - POC_PON dataset filename: kn199-04_POC_data_process.pdf (Portable Document Format (.pdf), 196.13 KB) MD5:ef052e36dd1e07e5807fb39209e89adb Processing and calibration information for the GT10 - POC_PON dataset.

More Information about this dataset

Funding Sources

Funding Source	Award Number
National Aeronautics & Space Administration	NNX09AN94G

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
KN199-04	GA03 GT10 USGT-NAT-2010 KN199-4 GNAT U.S. GEOTRACES NAZT Leg 1 knorr199-4/5 Section Cruise (GA03) 316N20101015	2010-10-15	R/V Knorr	William J. Jenkins (Chief Scientist) Edward A. Boyle (Co-Chief Scientist) Gregory A. Cutter (Co-Chief Scientist)	data info

Instruments

CHN Elemental Analyzer

Supplied Description:

Perkin Elmer CHNS/O Analyzer 2400 Series II:

The PE 2400 is a commercially available elemental analyzer that uses a combustion method to convert the sample elements to simple gases (CO2, H2O, and N2). The sample is first oxidized in a pure oxygen environment. Elements such as halogens and sulfur are removed by scrubbing reagents in the combustion zone. The resulting gases are homogenized and controlled to exact conditions of pressure, temperature, and volume. The homogenized gases are allowed to de-pressurize trough a column where they are separated in a stepwise, steady-state manner and measured as a function of their thermal conductivities.

Instrument Type

Generic Name: CHN Elemental Analyzer

Acronym: CHN_EA

Generic Description:

A CHN Elemental Analyzer is used for the determination of carbon, hydrogen, and nitrogen content in organic and other types of materials, including solids, liquids, volatile, and viscous samples.

Pump surface

Supplied Description:

NASA's surface peristaltic pump was used to collect some samples.

Instrument Type

Generic Name: Pump surface

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/31/

Generic Description:

A source of uncontaminated near-surface seawater pumped onto the deck of the research vessel that can be sampled and analyzed. This pumped seawater supply is from an over-the-side pumping system, and is therefore different from the vessel underway seawater system.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
lat	Latitude component of geographic position where samples were collected.	decimal degrees	lat
lon	Longitude component of geographic position where samples were collected.	decimal degrees	lon
time_gmt	Time of sampling, reported in GMT. in the format hhmm	unitless	time_gmt
yrday_gmt	Year day recorded in GMT time, where Jan 1 is day 1.	unitless	yrday_gmt
date_gmt	Date, recorded in GMT time. in the format yyyymmdd	unitless	date_gmt
depth	Sample depth in meters.	meters	depth
POC	Particulate organic carbon	milligrams/m^3	POC
POC_sd	Standard deviation of POC measurements.	milligrams/m^3	particulates_sd
PON	Particulate organic nitrogen.	milligrams/m^3	PON
PON_sd	Standard deviation of PON measurements.	milligrams/m^3	particulates_sd
replicate	A number indicating how many replicate samples were averaged to produce the reported value.	dimensionless	replicate
cruise_id	Official cruise identifier e.g. KN199-04 = R/V Knorr cruise number 199-04.	dimensionless	cruise_id
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
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. 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. PI-supplied values were identical to those in the intermediate US GEOTRACES master file Originally submitted as 'sample_no'; this parameter name has been changed to conform to BCO-DMO's GEOTRACES naming conventions. Unique sample identifier, where sample numbers from station 1 were collected with WHOI's GEOTRACES pump and samples for stations > 1 were collected with NASA's surface peristaltic pump. Samples with a GEOTRACES sample number also had pigment samples collected, missing sample numbers (nd) did not.	dimensionless	station
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	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	bottle
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
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) format: YYYY-MM-DDTHH:MM:SS[.xx][+/-TZ]	yyyy-MM-dd'T'HH:mm:ss.SS'Z'	ISO_DateTime_UTC

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