Metadata Report for BODC Series Reference Number 2107241

• 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

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.

JC077 Hydrochemical analysis of CTD bottle samples

Originator's Protocol for Data Acquisition and Analysis

Typically five water depths were sampled; 4 bottom water samples at 2 m intervals from the seafloor and one surface water (5 m depth). Water samples were retained for dissolved trace metal, DIC, nutrient, carbon isotopic, oxygen, total alkalinity, CO₂, CH₄ and ammonium analyses.

Samples for CO₂ and CH₄ analysis were the first to be collected from each CTD in 500 ml blood bags using silicon tubing. Seawater was carefully collected to avoid contact with the atmosphere and the formation of bubbles within the blood bags. 60 ml of nitrogen headspace was then introduced to all blood bags and the bags were then allowed to equilibrate at 24°C for at least 2 hours.

Concentrations were determined by gas chromatography using a headspace equilibration method with a reported accuracy and precision of less than 1 percent;. For this 20 ml of headspace gas was injected through a short desiccating column into a GC-FID. Methane and carbon dioxide headspace concentrations were determined from the area of peaks consistently produced at retention times of 1.68 (CH₄) and 4.76 (CO₂) minutes respectively. Peak heights were calibrated daily using 3 standards (a blank of pure N₂, 20 ppm CH₄ and 10 ppm CO₂ plus CH₄ 500 ppm CO2) and an atmospheric measurement. Every 10 samples the 10 ppm CH₄ and 500 ppm CO₂ was re-run to check for instrument drift.

Samples for dissolved oxygen concentration measurements were collected in 100 ml glass bottles immediately after sampling of CO₂/CH₄. 1 ml MnCl₂ and 1 ml NaOH/NaI was added on deck and the solutions shaken vigorously until well mixed. Samples were re-shaken 20 minutes later and allowed to settle for >8 hours. Dissolved oxygen was then determined by the Winkler titration (Winkler 1888, detection limit 1 µmol O₂ L^-1).

DIC samples were collected in 40 ml supra seal screw cap vials and methane in 100 ml glass bottles with a supra seal crimped top. Both samples were collected using silicone tubing with care to avoid the formation of bubbles. To minimise contact with the atmosphere at least twice the volume of the containers was allowed to overflow. Once sealed 10 µL HgCl was added though the supra seal and the samples were refrigerated at 4°C.

Water samples were also retained for nutrient, ammonium, alkalinity and trace metal analysis. Water for nutrient analysis was collected in 30 mL plastic vials and frozen at -20°C. Alkalinity samples were collected in 30 mL plastic vials and measured via titration with HCl using a mixture of methyl red and methylene blue as indicator and calibrating against the IAPSO seawater standard. Further information and detail can be fount in the cruise report

References Cited

Winkler. L.W. 1888. Die Bestimmung des im Wasser gelösten Sauerstoffes. Berichte der deutschen chemischen Gesellschaft, 21(2), 2843-2854.

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures.

The parameters loaded and any conversions applied are as follows:

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 JC077_CTD_JC077-CTD033

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: JC077_CTD_JC077-CTD033

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

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