Metadata Report for BODC Series Reference Number 2122329

• 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

Non-toxic (underway) sea water supply

A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.

RRS Discovery Cruise D321 (D321A) Discrete inorganic nutrient (nitrate, silicate and phosphate) concentrations from thermosalinograph bottle samples

Originator's Data Acquisition and Processing

Sampling Strategy

Several inorganic nutrient bottle samples were taken each day from the non-toxic supply. Sampling commenced on the 26/07/2007 and ended on the 20/08/2007.

Materials and Methodology

Samples for underway analysis were drawn directly from a non-toxic seawater tap within the lab into 25 ml sterilin coulter counter vials. The water has been pumped from below the ship from 5 m depth. These samples were refrigerated at approximately 4°C until analysis. Analysis commenced within 24 hours for all samples. Nutrient concentration was determined using a Scalar Sanplus Autoanalyser following the methods described by Kirkwood (1996) with the exception that the pump rates through the phosphate line are increased by a factor of 1.5. Further information on methodology and the performance of the autoanalyser can be found from page 201 of the cruise report.

Data Processing

Data processing was undertaken using Skalar propriety software and was done within 72 hours of the run being finished. The limits of detection were defined as twice the level of background noise averaged out over the course of the cruise. The background noise levels in digital units (the arbitrary unit used by the skalar autoanalyser software) were measured at the start and at the end of 10 of the 37 runs performed during the cruise. These were then averaged to give an averaged background noise level for the whole cruise. This number was then multiplied by 2. The concentration per digital unit was taken from the calculations used to determine the blank nutrient level in the artificial seawater matrix. Multiplying this number by the concentration per unit gives the limit of detection as follows.

^* The limit of detection for nitrate and silicate can be taken as 0.1 µmol l^-1 as visual inspection of the peaks clearly indicates that peaks down to this level are attributable to samples rather than fluctuations in the noise. This is because of the length of time over which the samples are analysed.

The errors for the nutrient analysis were worked out using a duplicate set of samples run during each analysis. A drift sample was included in each analysis to indicate if the baseline moves over the course of the run. These drift samples are included in pairs, i.e. 2 drift samples from the same batch are run one after the other. The first pair of these drifts was used as the duplicate samples in each of the 18 analyses. The error for the each analysis was determined using equation (1) where A is the largest of the duplicates and B is the smallest. These errors were then averaged over the cruise to obtain the error for the whole cruise.

Equation (1):

((A-B)/((A+B)/2))100

BODC Data Processing

Data arrived at BODC in a Microsoft Excel spreadsheet containing all the samples taken during the cruise.

A total of 260 underway samples were reported to have been taken in the cruise report (p201), however, a number of these were duplicate analyses made from the same bottle sample. Replicate analyses were subsequently averaged during BODC data processing resulting in 253 samples. The spreadsheet was initially converted into a Comma Separated Values format file (.csv) and appropriate BODC parameter codes were subsequently assigned. The following table shows how the variables supplied were mapped to BODC parameter codes.

Data below the detction limit specified by the data originator were flagged with the appropriate flag. Duplicate analyses from the same bottle sample were averaged. The overall result was a .csv file containing only one phosphate, nitrate and silicate measurement per bottle sample collected. Using this file, data were screened visually by plotting a time series in Microsoft Excel and appropriate BODC quality control flags were assigned. Subsequently, data and corresponding flags were loaded into BODC's database without any other changes.

Data Quality Report

None

Problem Report

None

References

Kirkwood, D., 1996. Nutrients: Practical notes on their determination in sea water. ICES techniques in marine environmental sciences. No. 17, 25pp.

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

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: