Metadata Report for BODC Series Reference Number 1989472

• 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.

D350 Discrete CTD Oxygen Sampling Document

The following information contains extracts from the D350 cruise report.

Originator's Protocol for Data Acquisition and Analysis

Water samples were collected for determination of dissolved oxygen concentrations, with a view to calibration of the CTD dissolved oxygen sensor. Water samples for determining dissolved oxygen concentrations were only taken from the deep stainless steel CTD casts as they were the first samples to be drawn from the Niskin bottles. Sampling were split across all depths. On casts where all twenty four Niskin bottles were sampled, depths were often doubled up so there were still at least two samples from each depth. The samples were drawn through short pieces of silicon tubing into clear, pre-calibrated, wide-necked glass bottles. The temperature of the water sample at the time of sampling was measured using an electronic thermometer probe. The temperature would be used to calculate any temperature dependant changes in the sample bottle volumes. Each of the samples was fixed immediately using 1 ml of manganese chloride and 1 ml of alkaline iodide. The samples were shaken thoroughly and left to settle for approximately thirty minutes before being shaken again. The samples were then left for at least an hour before analysis but all were analysed within twelve hours.

Sample analysis

The samples were analysed in the chemistry laboratory following the procedure outlined in Holley and Hydes (1995). The samples were acidified using 1 ml of sulphuric acid immediately before titration and stirred using a magnetic stirrer. Oxygen concentration was determined with equipment supplied by Metrohm UK Ltd using the Winkler whole bottle titration method with amperometric endpoint detection.

BODC Data Processing Procedures

The data were supplied to BODC in Microsoft Excel format and values were extracted and reformatted prior to being loaded into BODC's ocean database under the ORACLE Relational Database Management System. Data that were considered unrealistic were flagged suspect.

Content of data series

The Originator's variables were mapped to appropriate BODC parameter codes as follows:

Data Quality

None.

References

Holley, S.E. and Hydes, D.J., 1995. Procedures for the determination of dissolved oxygen in seawater, James Rennell Centre for Ocean Circulation, Internal Document.

Moore, M. (2010). RRS Discovery D350 Cruise Summary Report National Oceanography Centre, Southampton.

Project Information

Iron Biogeochemistry in the high latitude North Atlantic - Irminger Basin Iron Study (IBIS)

Funding

Funding was provided by NERC, in the form of four standard (full Economic Cost - fEC) grants with a total value of £528,607. The project was a study of the iron (Fe) biogeochemistry in the high latitude North Atlantic, with the results providing a better understanding of the role that nutrients like iron play in the growth of phytoplankton cells in the ocean. The gathered data were intended to help computer modellers to design improved climate models that would allow for better predictions of the extent of climate change over the next hundreds of years.

Project dates - 21 June 2007 to 08 November 2013.

Background

With the rise in carbon dioxide concentrations throughout the world, the importance of carbon-ingesting marine plants, such as phytoplankton is becoming more important. As phytoplankton take up atmospheric carbon dioxide, they are helping to reduce the atmospheric concentration. Recently it has been discovered that the phytoplankton in many of the world's oceans are lacking in iron. For example, in the Southern Ocean, phytoplankton cell growth is limited by very low iron concentrations. Thus, they do not remove as much carbon dioxide as they could. Recent studies have suggested that iron may even play a role in the phytoplankton growth in the high latitude North Atlantic, which was thought to be iron replete.

Objectives

The main objective of this project was to study the iron biogeochemistry of the high latitude North Atlantic, assess whether community productivity in parts of the high latitude North Atlantic was iron limited following the annual spring bloom, and to determine the factors which lead to this situation. This project studied whether iron was limiting phytoplankton growth in the study area, by undertaking two cruises and taking samples of water, sedimenting material, and atmospheric dust and rain. The project also directly investigated whether iron is limiting the growth of phytoplankton in water samples from the study area.

Participants

• University of Southampton, School of Ocean and Earth Science.
• University of Liverpool, Earth Surface Dynamics.
• University of Essex, Biological Sciences.
• University of East Anglia, Environmental Sciences.

• Prof. Eric Achterberg, University of Southampton, School of Ocean and Earth Science (Principal Investigator)
• Dr. Gary Fones, University of Portsmouth, School of Earth and Environmental Sciences
• Dr. Richard Sanders, National Oceanography Centre, Science and Technology
• Dr. Christopher Mark Moore, University of Southampton, School of Ocean and Earth Science
• Prof. Richard Geider University of Essex, Biological Sciences
• Prof. Tim Jickells, University of East Anglia, Environmental Sciences
• Prof. Ric Williams, University of Liverpool, Earth, Ocean and Ecological Sciences

Methodology

• Took samples of water, sediments, atmospheric dust and rain.
• Calculated the supply ratios of iron (Fe) to nitrogen (N), phosphorus (P) and carbon (C) to the surface oceans and in sedimenting material.
• Calculated the oceanic transfers of these elements using models.
• Assessed whether iron was limiting phytoplankton growth using both models and water samples analysis.

More information can be found within the Gateway to Research website.

Fieldwork

Two research cruises

• RRS Discovery D350 - 26 April 2010 to 09 May 2010. Departed from Govan, UK and arrived in Reykjavík, Iceland. Study area: North Atlantic Ocean - Irminger and Iceland Basins. Principal Scientist: Dr. Mark Moore, University of Southampton.
• RRS Discovery D354 - 10 July 2010 to 11 August 2010. Departed from Avonmouth, UK and arrived in Birkenhead, UK. Study area: North Atlantic Ocean - Iceland and Irminger Basins. Principal Scientist: Prof. Eric Achterberg, University of Southampton.

Instrumentation

• Stainless Steel CTD rosette
• Titanium CTD rosette
• VM ADCP 75 kHz
• VM ADCP 150 kHz
• Stand Alone Pump Systems (SAPS)
• PELAGRA - Neutrally Buoyant Sediment Traps
• Trace metal clean tow fish
• Seasoar with CTD, fluorometer and Laser Optical Plankton Counter (LOPC)
• Zooplankton nets
• Underway - Navigation, surface and meteorology

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for D350_CTD_Ctd_S_010

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: D350_CTD_Ctd_S_010

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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