Metadata Report for BODC Series Reference Number 2117260

• 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

GV Instruments IsoPrime isotope ratio mass spectrometer

A laboratory benchtop isotope ratio mass spectrometer (IRMS) designed for isotope ratio measurements, which operates in dual inlet or continuous flow modes. It forms part of the IsoPrime system which has a range of sample preparation and purification modules that can be coupled with the IsoPrime IRMS. The modules can analyse a range of samples (solids, liquids or gases) and each prepares the sample to be introduced into the IRMS as purified gases. The resultant prepared gases such as H₂, CO₂, CO, N₂, SO₂ or N₂O are then ionised and analysed for their isotopic content by the IRMS.

The instrument was originally manufactured by GV instruments as part of the IsoPrime series, but this part of the business was sold to Isoprime Ltd (a group member of Elementar Analysensysteme GmbH) in 2008. This model is no longer in production.

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 measurements of ¹⁵N and ¹³C uptake (specific incubations) from CTD bottles

Originator's Protocol for Sampling strategy and Analysis

Rates of nitrogen fixation and nitrate and carbon uptake were measured via a series of simulated in-situ on-deck incubations using standard stable isotope techniques (¹⁵N₂, ¹⁵NO₃, ¹³C). A typical sampling strategy saw water collected every other day from four light depths from the early morning CTD cast. The depths sampled corresponded to irradiance depths of 55%, 33%, 14% and 1% of surface irradiance. Incubations for nitrate and carbon uptake were limited to 6 hours or less.

Further details of the sampling technique can be found in the cruise report and in Painteret. al (2013).

Observations of nitrate and carbon were made for the following CTD profiles:

• CTD003
• CTD007
• CTD011
• CTD016
• CTD044
• CTD051
• CTD071
• CTD075
• CTD079

After incubation, all samples were gently filtered onto ashed (450°C, > 6 h) 25 mm GF/F filters, rinsed with a weak (1%) HCl solution to remove inorganic carbon and residual incubation water enriched in ¹⁵N/¹³C and frozen at -20°C. Upon return to shore, all filters were oven-dried (40°C) overnight and pelleted into tin capsules using a laboratory press, then analysed for carbon and nitrogen abundance and isotopic content on a GV Isoprime mass spectrometer coupled to a Eurovector elemental analyser. All analyses were conducted using a laboratory elemental and isotopic standard (tyrosine) to monitor for instrumental drift.

The methodology is based on Dugdale and Goering (1967) with adaptations of Slawyk et al. (1977). The full methodology and results are described in Painter et al. (2013)

References

Dugdale, R.C. and Goering,J.J. (1967) Uptake of new and regenerated forms of nitrogen in primary productivity. Limnology and Oceanography, 12(2), 196-206.

Slawyk, G., Collos,Y. and Auclair,J. (1977) The use of the ¹³C and ¹⁵N isotopes for the simultaneous measurement of carbon and nitrogen turnover rates in marine phytoplankton. Limnology and Oceanography, 22, 925-932.

Painter,S.C., Patey,M.D., Forryan,A. and Torres-Valdes,S. (2013). Evaluating the balance between vertical diffusive nitrate supply and nitrogen fixation with reference to nitrate uptake in the eastern subtropical North Atlantic Ocean. Journal of Geophysical Research 118, 5732-5749, doi: 5710.1002/jgrc.20416.

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures. The source file was the most processed and accurate version of the data.

The originator's parameters were mapped to BODC parameters as below:

Data quality

No issues identified

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_CTD075

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