Metadata Report for BODC Series Reference Number 1916882

• 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

Metrohm 916 Ti-Touch compact potentiometric titrator

The Metrohm 916 Ti-Touch is a stand-alone potentiometric titrator for dynamic (DET), monotonic (MET), set endpoint (SET) and manual titrations (MAT). The instrument consists of an intergrated buret, rod stirrer (or magnetic stirrer) and dosing system with a live touch control display.

Specifications

More information can be found in the manufacturer's product description.

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.

JC165 CTD Bottle Oxygen Sample Processing

Originator's Protocol for Data Acquisition and Analysis

During CTD deployments 20L Niskin bottles were fired at a variety of depths. Samples were extracted from each bottle for Oxygen analysis. These oxygen readings were used to calibrate the CTDs oxygen sensor.

In total 100 samples from 13 CTD stations were analysed for dissolved oxygen using a modified Winkler technique. An amperometric end point method was used, following the titration using an electrode to a set end point. Thiosulphate titrant was delivered using the new Metrohm 916 Ti-Touch compact potentiometric titrator (full duplicates were taken on cast 03 to check the Ti-touch alongside the Titrino 794, the results were identical and the Ti-touch was used throughout the rest of JC165). The method was standardised using 1ml additions of 0.01N OSIL iodate (3 bottles were used during JC165). The normality of the thiosulphate was 0.0987 ± 0.0007.

Duplicate samples were taken on each cast (usually from the deepest depth). The average duplicate difference was 0.76 µmol/l (0.3%).

BODC Data Processing Procedures

Data received were loaded into the BODC database using established BODC data banking procedures. Any replicates were averaged and standard deviation calculated. Details of mapping between originator's channels and BODC's parameter codes are given below:

Project Information

Marine LTSS: CLASS (Climate Linked Atlantic Sector Science)

Introduction

CLASS is a five year (2018 to 2023) programme, funded by the Natural Environment Research Council (NERC) and extended until March 2024.

Scientific Rationale

The ocean plays a vital role in sustaining life on planet Earth, providing us with both living resources and climate regulation. The trajectory of anthropogenically driven climate change will be substantially controlled by the ocean due to its absorption of excess heat and carbon from the atmosphere, with consequent impacts on ocean resources that remain poorly understood. In an era of rapid planetary change, expanding global population and intense resource exploitation, it is vital that there are internationally coordinated ocean observing and prediction systems so policy makers can make sound evidence-based decisions about how to manage our interaction with the ocean. CLASS will underpin the UK contribution to these systems, documenting and understanding change in the marine environment, evaluating the impact of climate change and effectiveness of conservation measures and predicting the future evolution of marine environments. Over the five-year period CLASS will enhance the cost-effectiveness of observing systems by migrating them towards cutting edge autonomous technologies and developing new sensors. Finally, CLASS will create effective engagement activities ensuring academic partners have transparent access to NERC marine science capability through graduate training partnerships and access to shipborne, lab based and autonomous facilities, and modelling capabilities.

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for JC165_CTD_JC165-032

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: JC165_CTD_JC165-032

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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