Metadata Report for BODC Series Reference Number 2124963

• 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.

Oxygen concentration by Winkler titration from discrete bottle samples on UK SOLAS cruise D326

Originator's Data Acquisition and Analysis

Around six oxygen samples were drawn from deployments of the stainless steel CTD rig, giving a total of 267 samples. Sampling depths were chosen for having minimal oxygen gradients, judged in near real time from the CTD in situ oxygen sensor data profile. Samples were drawn through silicone tubing into pre-calibrated glass bottles. Each sample immediately was fixed with manganese chloride, then stored for several hours before analysis.

Analysis followed the method of Holley and Hydes (1995). Samples were acidified with 1 ml sulphuric acid immediately prior to Winkler whole bottle titration using amperometric end point detection (Culberson and Huang, 1987). The measurements were calibrated to account for degradation of the sodium thiosulphate titrant.

References cited

Culberson, C.H., Huang, S., 1987. Automatic amperometric oxygen titration. Deep Sea Research A, 34, 875-880.

Holley, S.E., Hydes, D.J., 1994. Procedures for the determination of dissolved oxygen in seawater, James Rennell Centre for Ocean Circulation.

BODC Data Processing Procedures

Data were received by BODC in a Microsoft Excel spreadsheet (D326oxygen.xls), which contained measured oxygen concentration, and CTD cast identifier, Niskin bottle number, and nominal sample depth. 52 of the samples were analysed in duplicate. BODC calculated and banked the means and standard deviations of these duplicate values.

Parameter codes defined in the BODC parameter dictionary were mapped to the variables as follows:

The data were banked according to BODC standard procedures for discrete sample data. Once tagged with the appropriate parameter code, the data were loaded into the BODC relational database.

Data Quality Report

No data quality issues to report.

Project Information

UK Surface Ocean Lower Atmosphere Study

The UK Surface Ocean Lower Atmosphere Study (UK SOLAS) is the UK's contribution to the international SOLAS programme.

UK SOLAS formed interdisciplinary teams to address three primary aims

• To determine the mechanisms controlling rates of chemical transfer and improve estimates of chemical exchanges
• To evaluate the impact of these exchanges on the biogeochemistry of the surface ocean and lower atmosphere and on feedbacks between the ocean and atmosphere
• To quantify the impacts of these boundary layer processes on the global climate system

UK SOLAS started in 2003, to run for seven years. The programme was funded by the Natural Environment Research Council.

Funded projects

In total, 19 projects have been funded by UK SOLAS, over four funding rounds.

UK SOLAS has also supported ten tied studentships, and two CASE studentships.

Fieldwork

UK SOLAS fieldwork has included eight dedicated research cruises in the North Atlantic Ocean. Continuous measurements were made aboard aboard the Norwegian weather ship, Polarfront, until her decommission in 2009. Time series have been established at the SOLAS Cape Verde Observatory, and at the Plymouth Marine Laboratory L4 station. Experiments have taken place at the Bergen mesocosm facility.

A series of collaborative aircraft campaigns have added complementary atmospheric data. These campaigns were funded by UK SOLAS, African Monsoon Multidisciplinary Analyses (AMMA-UK), Dust and Biomass Experiment (DABEX) and the Facility for Airborne Atmospheric Measurements (FAAM).

Weblink: http://www.nerc.ac.uk/research/programmes/solas/

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for D326_CTD_16407A

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: D326_CTD_16407A

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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