Metadata Report for BODC Series Reference Number 2054472

• 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

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

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.

DY110 (AMT29) Winkler Titration Dissolved Oxygen Concentrations from CTD Bottles

Originator's Protocol for Data Acquisition and Analysis

Water samples were taken at a minimum of 6 and maximum of 15 depths at both pre-dawn (~4:00) and noon (~12:30) CTD stations during AMT29 (DY110). A single borosilicate glass bottle with a nominal volume of 150mL was filled directly from the CTD rosette Niskin bottle using a silicone tube, before other sampling occurred, at each depth. The bottle was allowed to overfill with 3 times its volume, from the bottom of the bottle to prevent the formation of bubbles. A traceable thermometer was used for measuring the fixing temperature (VWR TD 121, serial number: 92405158). Samples were fixed immediately, and placed underwater at room temperature until analysis within 24 hours of sampling (generally within 2 hours).

Dissolved O2 concentrations were determined by automated Winkler titration (Williams and Jenkinson, 1982), performed with a Metrohm 916 Ti-Touch with polarimetric end-point detection. Thiosulfate concentration was calibrated every 3 days using a commercial 0.1N KIO3 standard (Sigma-Aldrich, FIXANAL).

In total 435 samples were collected and analysed for calibration of the O2 sensor. After quality control on the Winkler-determined O2, 316 samples remained for the calibration.

References Cited

Williams P.J.LeB. and Jenkinson N.W. 1982. A transportable microprocessor-controlled precise Winkler titration suitable for field station and shipboard use. Limnology Oceanography 27: 576-584.

Instrumentation Description

Metrohm 916 Ti-Touch

Further information can be found here.

BODC Data Processing Procedures

Data were submitted to BODC during the cruise in an Excel spreadsheet for calibration of the Sea-Bird 43 oxygen sensor and archived under BODC accession number PML220048. Sample metadata (CTD cast, rosette bottle number, depth and date) were checked against information held in the database. Rosette position and depth were used to match the samples to those in the database. There were no discrepancies. The data were reformatted, assigned BODC parameter codes and loaded in BODC's samples database under Oracle Relational Database Management System.

A parameter mapping table template with an example row is provided below:

Data Quality Report

Several samples flagged by the originator were removed from the final dataset, because oxygen concentration values could not be derived due to instrument failure or compromised samples containing air bubbles. The raw data file is available on request.

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 DY110_CTD_CTD043

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: DY110_CTD_CTD043

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.