Metadata Report for BODC Series Reference Number 1347315

• 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.

RRS Discovery cruise D341 Ammonium concentrations from CTD bottles

Originator's Protocol for Data Acquisition and Analysis

Samples for Ammonium concentration analysis were collected from CTD casts profiled around the Porcupine Abyssal Plain (PAP) site. Niskin bottles were fired at predetermined depths and samples for several parameters were collected.

Data collected from 10 CTD casts were sent in a spreadsheet with accompanying metadata (Station ID, CTD bottle number and bottle depth) and quality flags.

The analysis methodology followed by the originator was based on the method of Holmes et al. (1999), in which ammonia reacts with OPA (orthophthalaldehyde) in a borate buffered solution in the presence of sulphite. The detailed protocol used slight modifications of the Holmes technique as recommended by Martin Johnson (UEA) and Stuart Painter (NOCS). The modified method used, 800 µL of the mixed reagent (made as in Holmes) per 10 mL of sample or standard, and after mixing the solution was allowed to stand for typically 3 hours at room temperature to allow the reaction to go to completion. Multiple blanks and standards as well as seawater fluorescence at the analytical wavelengths were determined. No detectable fluorescence above background was noted from the untreated seawaters and so no correction was applied. The detection limit of the method as used typically ranged from 10-20 nM (3 sigma blank), and this was adequate for the sampled upper water column. All handling steps were done in a laminar flow hood fitted with an ammonia absorbing filter pack on the inlet. Precision was improved by reusing the polystyrene diluvials in which the fluorescent product was formed. This infers there is a low level random contamination from the uncleaned diluvials.

References Cited

Holmes R.J., Aminot A., Kérouel R., Hooker B.A. and Peterson B.J., 1999. A simple and precise method for measuring ammonium in marine and freshwater ecosystems. Canadian Journal of Fisheries and Aquatic Sciences, 56 (10).

Instrumentation Description

Samples were analysed with a TD-700 Turner fluorometer fitted with a near UV mercury vapour lamp, an interference excitation filter at 350nm and a 410-600 nm combination emission filter.

BODC Data Processing Procedures

Data were received at BODC in a spreadsheet and originator's parameters were matched against BODC vocabulary dictionary and unit conversions applied. 8 samples were originally matched to OID 16475, but when cross-checking the metadata that was found not to be correct, as no CTD cast was performed and no samples were collected. The samples were matched against OID 16476.

The table below presents the matching between the originator's parameters and BODC codes for each variable:

Data Quality Report

A few samples were flagged by the originator as having improbable values (L) or being below the detection limit (<) and were kept in the BODC database. Samples that were below the detection limit but for which the originator did not provide any comments were also flagged accordingly.

For those samples where replicate measurements were sent, the average and standard deviation values were found and loaded. All average values that had a high standard deviation were assigned an M flag. The original measurements are available upon request.

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 D341_CTD_16476

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.

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: