Dataset: DOC and TOC near Station P

Name: DOC and TOC of seawater collected during CCGS John P. Tully cruises in the northeast Pacific Ocean from Vancouver Island to Station P from 2018 to 2020
Published: 2021-12-06
Keywords: Organic Carbon, North Pacific, Line P, EXPORTS, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.865829.1

Spatial Extent: N:50.613 E:-125.998 S:48.598 W:-145.002

Temporal Extent: 2018-09-13 - 2020-02-17

Project:

Constraining Upper-Ocean Carbon Export with Biogeochemical Profiling Floats (EXPORTS BGC Floats)

Principal Investigator:

Phoebe J. Lam (University of California-Santa Cruz, UCSC)

Co-Principal Investigator:

Andrea J. Fassbender (National Oceanic and Atmospheric Administration, NOAA-PMEL)

International Collaborator:

Sophia Johannessen (Fisheries and Oceans Canada, Pacific Region, DFO MPO)

Contact:

Sophia Johannessen (Fisheries and Oceans Canada, Pacific Region, DFO MPO)

Technician:

Jacqueline S. Long (Monterey Bay Aquarium Research Institute, MBARI)

Cynthia Wright (Fisheries and Oceans Canada, Pacific Region, DFO MPO)

BCO-DMO Data Manager:

Dana Stuart Gerlach (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2021-12-06

Restricted:

Validated:

Yes

Current State:

Final no updates expected

DOC and TOC of seawater collected during CCGS John P. Tully cruises in the northeast Pacific Ocean from Vancouver Island to Station P from 2018 to 2020

Abstract:

This dataset includes observations of dissolved organic carbon and total organic carbon from seawater samples collected during CCGS John P. Tully cruises from 2018 to 202 in the northeast Pacific Ocean from Vancouver Island to Station P.

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2021-12-06	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.865829.1	2021-12-20

Methods & Sampling

Samples
Sampling was conducted aboard the CCGS John P. Tully during five cruises (2018-2020) in the northeast Pacific Ocean from Vancouver Island to Station P (50°N, 145°W).
Fisheries and Oceans Canada (DFO) Cruise numbers: 2018-40, 2019-001, 2019-006, 2019-008, 2020-001

Seawater samples for dissolved and total organic carbon (DOC, TOC) were collected from 10 L Niskin bottles into pre-cleaned 40 mL scintillation vials, with 0.125 cm Teflon low-bleed septa. The vials had been cleaned in Extran 300 and rinsed several times with Type I Ultrapure water. Vials were then soaked in 10% HCl for a minimum of four hours and rinsed several times with Type I Ultrapure water. Cleaned vials were allowed to dry and were then baked at 450°C for a minimum of 5 hours. Septa were briefly washed in 10% HCl, rinsed with Type I Ultrapure water and allowed to air dry.

Samples for TOC were collected directly from the spigot of the Niskin bottle. Samples for DOC were filtered through a Millipore Opticap XL Durapore 0.22 µm inline filter cartridge (Product No. KVGLA04HH3) attached to the spigot. Vials were rinsed three times with sample water and then filled to about three-quarter capacity, to avoid breakage during freezing. The samples were quick-frozen immediately after collection, using a stainless-steel freezer block, and then stored frozen at -20°C until analysis.

DOC and TOC were measured at the Institute of Ocean Sciences, using a Shimadzu TOC-L DOC/TOC analyzer (measurement reproducibilty of ± 1.5 %), following Standard Operating Procedure 7 from Chapter 4 in Dickson et al. (2007), with the following modifications: 1) sulphuric acid was used in place of phosphoric acid to reduce vitrification of the column with saline samples; and 2) the sparging time was increased to 150 seconds.

Standards

A 1000ppm standard of potassium hydrogen phthalate was prepared using Type 1 water (defined below). The standard stock solution was stored refrigerated for up to 2 months.
Standard dilutions were done by calibrated pipette into volumetric flasks. They were made with Type 1 water that had been further processed to reduce TOC into the 2-3 ppb range. Dilution standards have a shelf life of two weeks. The very low standard concentrations (0.1-0.5 ppm) were made in larger volume flasks to reduce the errors associated with pipetting small amounts.
Type I - Ultrapure, Type I water is defined by the American Society for Testing and Materials (ASTM) as having a resistivity of >18 MΩ-cm, a conductivity of <0.056 µS/cm and <50 ppb of Total Organic Carbons (TOC).
Low Carbon Water (LCW) is a purchased, 2 μM, reference standard used to determine the instrument blank. Miami Seawater is a purchased, 42-45 μM, reference standard used to determine when the column/instrument was running cleanly enough to measure low concentrations in seawater.

Data Processing Description

Raw voltage peak areas were converted to organic carbon concentration, using a standard curve (0–176.7 μM). The calculated concentration of the LCW water minus 2 μM was subtracted as an instrument blank. Calculations were done using Microsoft Excel.

Problem/Error report:
Data from a few stations were omitted. These reflected missing data or suspected mislabeling of samples.

=================
BCO-DMO Processing:

Imported data from source file "LineP_DOCTOC.xlsx.xlsx" into the BCO-DMO data system.
Data file imported using missing data identifier "NaN”. The missing data identifier "NaN" in the original source file will be displayed as appropriate based on the type of file you download from the BCO-DMO data system. For example, missing data will be shown as blank (null) values in the csv files. In MATLAB .mat files it will be displayed as NaN. When viewing data at BCO-DMO the missing value will be shown as "nd" meaning "no data."
Combined separate date and time columns to single datetime column with ISO8601 format.
Added column for vessel/ship
Added conventional header with dataset name, PI name, version date.
Modified parameter (column) names to conform with BCO-DMO naming conventions. (The only allowed characters are A-Z,a-z,0-9, and underscores. No spaces, hyphens, commas, parentheses, or Greek letters).

Data Files

File
doc_toc.csv (Comma Separated Values (.csv), 27.34 KB) MD5:9641491bf8e77791cf5a94d300e3545c Primary data file for dataset ID 865829

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-2032754
NSF Division of Ocean Sciences	OCE-1756932

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
Line-P_cruises			CCGS John P. Tully		data info

Instruments

Niskin bottle

Supplied Description:

Seawater samples for dissolved and total organic carbon were collected from 10 L Niskin bottles

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.

Shimadzu TOC-L Analyzer

Supplied Name: Shimadzu TOC-L DOC/TOC analyzer

Supplied Description:

DOC and TOC were measured at the Institute of Ocean Sciences, using a Shimadzu TOC-L DOC/TOC analyzer

Instrument Type

Generic Name: Shimadzu TOC-L Analyzer

Acronym: Shimadzu TOC-L

Community Identifier: http://onto.nerc.ac.uk/CAST/124.html

Generic Description:

A Shimadzu TOC-L Analyzer measures DOC by high temperature combustion method.

Developed by Shimadzu, the 680 degree C combustion catalytic oxidation method is now used worldwide. One of its most important features is the capacity to efficiently oxidize hard-to-decompose organic compounds, including insoluble and macromolecular organic compounds. The 680 degree C combustion catalytic oxidation method has been adopted for the TOC-L series.

http://www.shimadzu.com/an/toc/lab/toc-l2.html

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
ISO_DateTime_UTC	Date and time in ISO8601 standard format (YYYY-MM-DDThh:mm:ssZ) Format: %Y-%m-%dT%H:%M:%SZ	unitless	ISO_DateTime_UTC
Vessel	Vessel	unitless	ship
Cruise_ID	Cruise	unitless	cruise_id
Station	Station number	unitless	station
Sample_Number	Sample number	unitless	sample
Latitude	Latitude of sample collection	decimal degrees	lat
Longitude	Longitude of sample collection	decimal degrees	lon
Depth	Depth of sample collection	meters (m)	depth
DOC	Dissolved organic carbon	micromoles (uM)	DOC
DOC_QF	Quality Flag for DOC measurement where 2=acceptable; 3=questionable; 4=bad; 5=not reported; 6=mean of replicates; 9=not sampled	unitless	q_flag
TOC	Total organic carbon	micromoles (uM)	TOC
TOC_QF	Quality Flag for TOC measurement where 2=acceptable; 3=questionable; 4=bad; 5=not reported; 6=mean of replicates; 9=not sampled	unitless	q_flag

Status message

Database

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Dataset: DOC and TOC near Station P