Metadata Report for BODC Series Reference Number 1965193

• Metadata Summary

• Problem Reports

• Data Access Policy

• Data 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

COMICS research programme data access conditions - phase 1

These data are currently restricted to the COMICS Community.

Data Policy

COMICS Data Policy - phase 1

These data are currently restricted to the COMICS Community. The restriction timeline is based on the data submission/accession date due to the amount of time taken to work up some of the data. Individual datasets are restricted to the COMICS project participants for two years after their accession date.

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.

Turner Designs Trilogy Fluorometer

The Trilogy Laboratory Fluorometer is a compact laboratory instrument for making fluorescence, absorbance and turbidity measurements using the appropriate snap-in Application Module.

The following snap-in application modules are available:

For extracted chlorophyll measurements using EPA 445, Trilogy automatically calculates the concentration using the filtered and solvent volumes. The turbidity modules use an IRLED with a wavelength of 860nm to meet ISO 7027 standards for turbidity water quality measurements.

Specifications

Further details can be found in the manufacturer's specification sheet.

RRS Discovery Cruise DY086 CTD Bottle Chlorophyll-a Samples

Originator's Protocol for Data Acquisition and Analysis

Chlorophyll-a samples were collected during cruise DY086 between November 12^th 2017 and December 19^th 2017 to aid in calibrating the fluorometer on the CTD. Samples were obtained from a range of depths using an SBE 911plus Titanium or Stainless Steel CTD unit with 24 10L or 20L Niskin bottles fitted to the rosette sampler respectively. Between 100-250ml of seawater were filtered on GF/F filters for the total samples and polycarbonate 0.2µm, 2µm, and 10µm filters for size fractionated chlorophyll-a.

Chlorophyll-a was extracted in 6ml of 90% acetone after about 24 hours of refrigeration. Measurements were made using a Turner Designs Trilogy fluorometer. Both a Red Turner solid standard and an acetone blank sample were used at the start and end of each set of readings, both of these readings wre used in the Chlorophyll-a calculations seen in the following equation:

Chla = Dilution * (R)adj * (F-blank) * (v/V)

• Dilution = 1
• (R)adj = response factor adjusted for the shift in the solid standard
• blank = acetone blank reading
• v = acetone extracted volume (6ml)
• V = filtered sample volume in ml

BODC Data Processing Procedures

The chlorophyll data were supplied to BODC in an Excel spreadsheet. The data were loaded into BODC's database using established BODC data banking procedures with no changes.

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

Any flags on the originator's data were mapped to the appropriate equivalent BODC flags. Although some bottles were marked misfired by the originator, BODC did not apply any additional flags to the data from these bottles as the data may still be accurate.

The titanium CTD was used for casts 1, 4, 7, 15, 19, 24, 26, and 29.

Project Information

Controls over Ocean Mesopelagic Interior Carbon Storage: COMICS

COMICS is a four-year collaborative research project that aims to quantify the flow of carbon in the ocean?s ?twilight? zone in order to accurately model global climate change. This ?twilight? zone is the part of the ocean between 100m and 1000m below the sea surface, where only a small amount of light from the sun can still penetrate.

By investigating carbon dynamics in the ocean interior, COMICS will help to improve predictions of future global climate change.

The COMICS project is led by the National Oceanography Centre and is a collaboration between the British Antarctic Survey and the universities of Queen Mary London, Liverpool, Oxford and Southampton. The project received funding from the Natural Environmental Research Council and runs between April 2017 and 2021.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for DY086_CTD_CTD002

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: DY086_CTD_CTD002

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.