Metadata Report for BODC Series Reference Number 2283976

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

Marianda Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity (VINDTA) 3C

The VINDTA 3C (Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity) is a laboratory alkalinity titration system combined with an extraction unit for coulometric titration, which simultaneously determines the alkalinity and dissolved inorganic carbon content of a sample. The sample transport is performed with peristaltic pumps and acid is added to the sample using a membrane pump. No pressurizing system is required and only one gas supply (nitrogen or dry and CO2-free air) is necessary. The system uses a Metrohm Titrino 719S, an ORION-Ross pH electrode and a Metrohm reference electrode. The burette, the pipette and the analysis cell have a water jacket around them. Precision is typically ± 1 µmol kg^-1 for TA and/or DIC in open ocean water.

Further details can be found in the manufacturer's brochure.

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

UKOA JR271 dissolved inorganic carbon (DIC) and total alkalinity (TA) concentrations from CTD bottle and underway samples

Originator's Protocol for Data Acquisition and Analysis

Sampling from the CTD Rosette for DIC and TA - Water samples for the determination of DIC and alkalinity were drawn from the 20 l Niskin bottles on the CTD rosette and collected in 250 ml glass bottles with ample rinsing and overflowing to avoid gas exchange with the air. Two replicate 250 ml samples were collected per Niskin. Most CTD stations and most depths were sampled. Leaking Niskins were not sampled. About 60 CTD casts with typically 6 to 8 Niskins per cast were sampled and analysed on board, equivalent to about 420 samples. The samples were poisoned with a saturated mercuric chloride solution (50 µl per 250 ml sample).

Surface water sampling for DIC and TA - Two hourly water samples for the determination of DIC and alkalinity were drawn from the non-toxic surface water supply in the deck laboratory. Parallel sampling was undertaken for nutrients and salinity (4 times per day). The series was extended to also include samples for the microscopic determination of plankton species during the second half of the cruise. The DIC and alkalinity samples were collected in 250 ml glass bottles with ample rinsing and overflowing to avoid gas exchange with the air. Two replicate 250 ml samples were collected every two hours, equivalent to 323 samples throughout the cruise. The samples were poisoned with a saturated mercuric chloride solution (50 µl per 250 ml sample).

Dissolved Inorganic Carbon and Total Alkalinity measurements -

The DIC concentration was determined by coulometry after the method of Johnson et al. (1987). Generally all samples from two stations were run on one coulometer cell (#7). Two to three CRMs (Certified Reference Material, batch 107) were used per coulometric cell and station. The average of the two DIC replicates was used.

The alkalinity measurements were made by potentiometric titration. The acid consumption up to the second endpoint is equivalent to the titration alkalinity. The systems use a Metrohm Titrino 719S for adding acid, an ORION-Ross pH electrode and a Metrohm reference electrode. The burette, the pipette (volume approximately 100 ml), and the analysis cell have a water jacket around them. The titrant (0.1 M hydrochloric acid, HCl) was made at UEA. The average of the two alkalinity replicates was used.

The VINDTA instruments performed well during the cruise. Problems included a broken Peltier element (#4), failing level sensors for pipette full and cell full (#4, #7), a malfunctioning temperature sensor (#4) and rough sea state reduced the accuracy of TA and DIC analyses.

Instrumentation Description

Water samples were analysed for DIC and TA on two VINDTA instruments. The VINDTA combined DIC/alkalinity instruments (#4 and #7, version 3C) operate at 25°C (Mintrop, 2004). Most CTD samples were analysed on one instrument (#7) and most underway samples on the second instrument (#4).

BODC Data Processing Procedures

Data were submitted via email in an Excel spreadsheet archived under BODC's accession number SOC120231. Sample metadata (Cruise, Latitude, Longitude, Station, CTD cast, niskin bottle number and depth) were checked against information held in the database. There were no discrepancies.

The concentration data were provided in micro-moles per kilogram. These units match the BODC parameter code units and a unit conversion was not applied. Where only two replicates were analysed the means were supplied with the difference between the replicate values. Where more than two replicates were provided standard deviations were provided. Only the means and standard deviations were loaded to the database. The original submission file can be requested if required from BODC.

The data were reformatted and loaded in BODC's samples database under Oracle Relational Database Management System. Data were marked up with BODC parameter codes and loaded into the database.

A parameter mapping table is provided below;

Data Quality Report

The data originator provided a quality controlled data set. WOCE flags were converted to the appropriate BODC data quality flag.

Problem Report

Not relevant to this data set.

Project Information

UKOARP Theme B: Ocean acidification impacts on sea surface biology, biogeochemistry and climate

The overall aim of this theme is to obtain a quantitative understanding of the impact of ocean acidification (OA) on the surface ocean biology and ecosystem and on the role of the surface ocean within the overall Earth System.

The aims of the theme are:

• To ascertain the impact of OA on planktonic organisms (in terms of physiological impacts, morphology, population abundances and community composition).
• To quantify the impacts of OA on biogeochemical processes affecting the ocean carbon cycle (both directly and indirectly, such as via availability of bio-limiting nutrients).
• To quantify the impacts of OA on the air-sea flux of climate active gases (DMS and N₂O in particular).

The main consortium activities will consist of in-situ measurements on three dedicated cruises, as well as on-deck bioassay experiments probing the response of the in-situ community to elevated CO₂. Most of the planned work will be carried out on the three cruises to locations with strong gradients in seawater carbon chemistry and pH; the Arctic Ocean, around the British Isles and the Southern Ocean.

Weblink: http://www.oceanacidification.org.uk/research_programme/surface_ocean.aspx

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JR20120601_CTD_CTD017s

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: JR20120601_CTD_CTD017s

Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.