Metadata Report for BODC Series Reference Number 1852427

• 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.

D369 Nanomolar Dissolved Inorganic Nutrients

Originator's Protocol for Data Acquisition and Analysis

All apparatus coming into contact with the samples or reagents was cleaned by soaking in 1 M HCl and rinsing thoroughly with ultrapure water from a MilliQ system. Samples were taken from the CTD rosette using 60 mL acid-washed LDPE bottles, rinsing three times before filling, and were stored in the fridge until analysis. Analysis was typically undertaken within 12 hours, although for a few profiles sampled during the evening were not measured until the following afternoon (typically 18 - 20 hours later). For each CTD profile, typically 10 - 12 samples were taken, covering every, or almost every, unique depth. However, during periods of intense sampling (with 3 or more CTD profiles per day), this was reduced to between 5 and 7 samples per day.

Analysis for dissolved nitrate + nitrite (NO₂₊₃ ^-) and dissolved phosphate (PO₄ ^3-), or soluble reactive phosphate (SRP - the phosphorus fraction measured by the Molybdenum Blue technique), at nanomolar concentration were undertaken on a purpose-built, segmented-flow autoanalyser following a method described in Patey et al. (2008), with some changes to reagent flow rates. Two liquid waveguide capillary flow cells (LWCCs) were used to provide a two-metre path length, enabling the detection of nanomolar concentrations. A single tungsten-halogen lamp (HL2000-HP, Ocean Optics) provided illumination for both LWCCs, with a bifurcated fibre-optic cable being used to divide the light between the two channels. Two Ocean Optics USB spectrometers monitored the absorbance in each cell (USB2000 for phosphate and a USB4000 for nitrate / nitrite).

For 7 CTD profiles, nitrite was also measured, enabling the nitrite contribution to the nitrite + nitrate signal to be determined and thus the true nitrate concentration to be derived. Since only two channels were available, this was achieved by re-running the samples (together with an additional set of nitrite standards) at the end of the day with the cadmium column bypassed so that nitrate reduction does not occur. Samples were introduced manually by switching a sample line between a reference solution (low nutrient surface seawater) and sample or standard solution and the resulting change in absorbance was monitored. Absorbance versus time was continuously recorded for each channel and stored electronically in a plain text format. Calibration curves and results were generated manually from the peak heights using spreadsheet software.

References Cited

Patey, M.D., Rijkenberg, M.J.A., Statham, P.J., Mowlem, M., Stinchcombe, M.C. and Achterberg, E.P. 2008.Determination of nitrate and phosphate in seawater at nanomolar concentrations. Trends in Analytical Chemistry 27: 169-182.

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures. Data were loaded into BODC's database without any changes.

Originators parameters were mapped to BODC parameter codes as follows:

Data Quality Report

Some data had been highlighted by the originator to signify questionable data points or whole CTD casts that were considered 'bad', the BODC data flag 'L' has been applied to these data.

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

No Document Information Held for the Series

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: D369_CTD_CTD022

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.