Metadata Report for BODC Series Reference Number 1872649

• 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.

UKOA D366 dissolved methane (CH₄) and nitrous oxide (N₂O) concentrations from CTD bottle and bioassay samples

Originator's Protocol for Data Acquisition and Analysis

Samples were collected from 36 CTD profiles from between 1 and 10 depths for each CTD. Then 1 litre samples were equilibrated with compressed air and headspace analysis performed onboard using FID-gas chromatography and ECD-gas chromatography for CH₄ and N₂O respectively. Atmospheric concentrations were determined by the same methods using a pumped supply from the ships monkey island.

Additionally, methane and nitrous oxide were sampled from 5 bioassay experiments during the cruise, that were designed to evaluate the response of multiple organisms and processes to artificial carbonate system manipulation. An extra 3 nutrient addition experiments were also conducted onboard. The incubations were performed within a purpose-built experimental laboratory allowing acute temperature and light control. The temperature in the container was set to match the in situ at the time of the water collection. The light (100 µE. m-2. s-1) was provided by LED panels and remained constant through the cruise. A 14/8 h light/dark cycle was applied. Each of the 5 bioassays were run for 4 days with 2 time points: T1 (48h) and T2 (96h). In order to provide enough water to process the various analyses and to have triplicate of each measurement, 9 bottles were dedicated to each time point. A total of 72 bottles were set up for each bioassay and arranged on shelves in the container. At pre-dawn, surface water (~ 5m deep) was collected from Niskin bottles (24 X 20L) out of one single cast and immediately dispatched in transparent acid-cleaned 4L polycarbonate bottles on deck. The bottles were then wrapped individually in zip lock bags to avoid contamination pending carbonate chemistry manipulations. Bioassay samples were analysed in the same way as the CTD samples.

Instrumentation Description

FID-gas chromatography

ECD-gas chromatography

BODC Data Processing Procedures

Data were submitted via email in an Excel spreadsheet archived under BODC's accession number PML120178. Sample metadata (Date, Julian Day, Time, CTD cast, position, bottle number and depth) were checked against information held in the database. There were no discrepancies.

The concentration data were provided in nano-moles per litre. These units match the BODC parameter code units and a unit conversion was not applied. Where replicate measurements were provided the mean and standard deviation were calculated and loaded to the database.

The data were reformatted and loaded in BODC's samples database under Oracle Relational Database Management System. Data were marked up with BODC parameter codes and loaded into the database.

A parameter mapping table is provided below;

Data Quality Report

The data originator provided no comments on the data quality.

Problem Report

Not relevant to this data set.

Project Information

UKOARP Theme B: Ocean acidification impacts on sea surface biology, biogeochemistry and climate

The overall aim of this theme is to obtain a quantitative understanding of the impact of ocean acidification (OA) on the surface ocean biology and ecosystem and on the role of the surface ocean within the overall Earth System.

The aims of the theme are:

• To ascertain the impact of OA on planktonic organisms (in terms of physiological impacts, morphology, population abundances and community composition).
• To quantify the impacts of OA on biogeochemical processes affecting the ocean carbon cycle (both directly and indirectly, such as via availability of bio-limiting nutrients).
• To quantify the impacts of OA on the air-sea flux of climate active gases (DMS and N₂O in particular).

The main consortium activities will consist of in-situ measurements on three dedicated cruises, as well as on-deck bioassay experiments probing the response of the in-situ community to elevated CO₂. Most of the planned work will be carried out on the three cruises to locations with strong gradients in seawater carbon chemistry and pH; the Arctic Ocean, around the British Isles and the Southern Ocean.

Weblink: http://www.oceanacidification.org.uk/research_programme/surface_ocean.aspx

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for D366_CTD_D366049

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: D366_CTD_D366049

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