Metadata Report for BODC Series Reference Number 1875740

• 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 supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

Narrative Documents

Metrohm 794 Basic Titrino Titrator

The Metrohm 794 Basic Titrino is an all-purpose titrator used for dynamic and monotonic determination of solution concentrations. Titration modes of the instrument are constant or depending on the titration curve variable dosing of the titration reagent and Endpoint-Titration. The operation modes include; Dynamic Equivalence-point Titration (DET), Monotonic Equivalence-point Titration (MET), Set Endpoint Titration (SET), pH Calibration (CAL), Measuring (MEAS) and Titration Procedure (TIP) which links various commands and methods to a titration procedure. All operating modes of the Titrino can be combined to perform extensive analytical sequences.

Ready-to-start methods for the most common applications are stored in the internal method memory for example; the determination of the hardness of drinking water, diazotation of sulfonamides and primary amines, and determination of the peroxid number of edible oil sand fats. The operator is free to modify and overwrite the methods or to create and store new titration sequences.

The instrument consists of an exchange unit with a small display, which can be connected to either a magnetic stirrer (728), propeller rod stirrer (802) or Ti stand (703 or 727). Data exchange with a PC is possible with the Metrodata VESUV Software and with Metrodata TiNet Software complete keypad remote control, data acquisition and evaluation via PC is enabled.

Further details can be found in the manufacturer's user manual.

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.

Discrete oxygen samples from CTD bottles from RRS James Cook cruise 31 (JC031)

Originator's Protocol for Data Acquisition and Analysis

Discrete oxygen samples were collected for the calibration of the CTD oxygen sensor. Water was collected from depth using a stainless steel CTD frame fitted with a Sea-Bird SBE 32, twenty-four way carousel (s/n 32-45661-0621) equipped with 24, twenty litre OTE external spring water samplers. However, due to the complete loss of the CTD package at station 12, water was subsequently collected using a stainless steel CTD frame fitted with a Sea-Bird SBE 32, twenty-four way carousel (s/n 32-19817-0243) equipped with 20, ten litre OTE external spring water samplers (rosette positions 1-20) and 4, twenty litre OTE external spring water samplers (rosette positions 21-24). Oxygen samples were analysed by Winkler titration method and amperometric endpoint detection. The titration unit used was a Metrohm 794 Basic Tritrino unit. More detailed information on the sampling and analysis of oxygen samples can be found in the cruise report from pages 38-39.

BODC Data Processing Procedures

Data arrived at BODC in 84 MSTAR NetCDF format files. The data received were loaded into the BODC database using established BODC data banking procedures. All data were screened in-houseprior to loading. The following discrepancies between the data originator's metadata and the metadata held centrally in the database were observed:

• Station number was converted to the BODC identification.

• Originator's quality control flags were converted to BODC quality control markers.

The following discrepancies between the data originator's data and the data held centrally in the database were observed:

• Oxygen concentrations were converted from the data originator's units (µmol/kg) to BODC units (µmol/l) using the data originator's conversion factor (see below). Both µmol/kg and µmol/l were loaded to the database.

• Nine oxygen concentrations (µmol/kg) were re-calculated in-house using oxygen concentrations (µmol/l) and oxygen fixation temperatures that were re-supplied by the data originators. The calculation used the data originator's conversion factor (see below). Re-calculation was necessary because erroneous, high (>100 °C) oxygen fixation temperatures (botoxytemp) had been used in the original calculation of µmol/kg. The problem was only identified after data submission to BODC. With the data originator's permission, the new data (oxygen concentration (µmol/l), oxygen fixation temperature and re-calculated oxygen concentration (µmol/kg)) were loaded to the database. The following BODC bottle identification codes were effected: 214650, 214702, 214787, 214810, 214835, 214859, 215095, 215164 and 215243.

• Absent data values were removed.

Originator's parameters were mapped with BODC codes as follows:

Unit conversions (Originator's conversion factor)

Oxygen units were converted from µmol/kg to µmol/l using µmol/l = (µmol/kg * (sigma_t+1000))/1000. Sigma_t was derived from the density of seawater at atmospheric pressure (Fofonoff and Millard, 1983) using the oxygen fixation temperature (botoxytemp) and the primary CTD upcast salinity (upsal) (Fofonoff and Millard, 1983). Details on the CTD sensors used can be found here.

References Cited

Fofonoff N.P. and Millard Jr. R.C., 1983. Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science, 44, 53pp.

Data Quality Report

Data quality good (BODC assessment). Data points that were marked during the originator's quality control process were considered questionable or bad. The originators discuss the quality of the sodium thiosulphate standardisation on pages 39-41 of the cruise report.

Problem Report

No major problems (BODC assessment)

Project Information

Oceans 2025 - The NERC Marine Centres' Strategic Research Programme 2007-2012

Who funds the programme?

The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).

Who is involved in the programme?

The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:

• National Oceanography Centre, Southampton (NOCS)
• Plymouth Marine Laboratory (PML)
• Marine Biological Association (MBA)
• Sir Alister Hardy Foundation for Marine Science (SAHFOS)
• Proudman Oceanographic Laboratory (POL)
• Scottish Association for Marine Science (SAMS)
• Sea Mammal Research Unit (SMRU)

Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:

• British Oceanographic Data Centre (BODC), hosted at POL
• Permanent Service for Mean Sea Level (PSMSL), hosted at POL
• Culture Collection of Algae and Protozoa (CCAP), hosted at SAMS

The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.

What is the programme about?

Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:

• improve knowledge of how the seas behave, not just now but in the future;
• help assess what that might mean for the Earth system and for society;
• assist in developing sustainable solutions for the management of marine resources for future generations;
• enhance the research capabilities and facilities available for UK marine science.

In order to address these aims there are nine science themes supported by the Oceans 2025 programme:

• Climate, circulation and sea level (Theme 1)
• Marine biogeochemical cycles (Theme 2)
• Shelf and coastal processes (Theme 3)
• Biodiversity and ecosystem functioning (Theme 4)
• Continental margins and deep ocean (Theme 5)
• Sustainable marine resources (Theme 6)
• Technology development (Theme 8)
• Next generation ocean prediction (Theme 9)
• Integration of sustained observations in the marine environment (Theme 10)

In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.

When is the programme active?

The programme started in April 2007 with funding for 5 years.

Brief summary of the programme fieldwork/data

Programme fieldwork and data collection are to be achieved through:

• physical, biological and chemical parameters sampling throughout the North and South Atlantic during collaborative research cruises aboard NERC's research vessels RRS Discovery, RRS James Cook and RRS James Clark Ross;
• the Continuous Plankton Recorder being deployed by SAHFOS in the North Atlantic and North Pacific on 'ships of opportunity';
• physical parameters measured and relayed in near real-time by fixed moorings and ARGO floats;
• coastal and shelf sea observatory data (Liverpool Bay Coastal Observatory (LBCO) and Western Channel Observatory (WCO)) using the RV Prince Madog and RV Quest.

The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JC031_CTD_CTD_001

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: JC031_CTD_CTD_001

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.