Metadata Report for BODC Series Reference Number 1639539

• 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

Teledyne RDI's Workhorse Long Ranger ADCP

The Workhorse Long-Ranger acoustic doppler current profiler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented broadband signal (75 kHz) and a standard depth rating of 1500m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

The instrument comprises:

• An aluminium transducer head with four beams at 20^o from the vertical in a convex configuration, temperature sensor, electronic assemblies, fluxgate compass, pitch and roll sensors
• 4 x 28 D-cell alkaline battery packs
• 40 MB PC card internal memory (upgradeable to 440 MB)
• 1500m depth rated 6061 aluminium pressure case. End cap with wet material connector and dummy plug

Wyville Thomson Ridge Moored Acoustic Doppler Current Profiler: Originator Processing

This document outlines the procedures undertaken by the data originator to process and quality assure ADCP data collected as part of a long-term monitoring programme studying transport across the Wyville Thomson Ridge.

Data Processing

The raw binary data are downloaded from the instrument and converted into Matlab format (one file per deployment) using Teledyne RDI-supplied WinADCP software.

Derived 2-dimensional parameters exported from WinADCP have had bin mapping applied to account for the complex geometry involved in extracting currents relative to earth coordinates. In addition the WinADCP software performs a number of calculations needed to determine velocities.

Wyville Thomson Ridge Moored Acoustic Doppler Current Profiler: Processing undertaken by BODC

Data are sent to BODC in .MAT format with one file provided for each ADCP mooring deployment. These files have undergone some initial processing using WinADCP software, but no detailed validation or correction to the data has subsequently been conducted by the data originator. The original .MAT files are archived at BODC and are available upon request.

A number of key parameters from the original .MAT files, as specified by the data originator, are then reformatted into QXF - a NetCDF subset. On occassion BODC have split the data into several files. During the reformatting exercise, bin depths are calculated in order to produce a 2-dimensional bin depth array:

Standard parameter codes, that accurately describe the data and any unit conversions, are assigned. These are detailed in the table below.

The data are screened visually and any spikes, or instrument malfunctions, are highlighted with BODC quality control flags. Series are trimmed at the start/end to remove phases from the mooring deployment/recovery. Subtle/brief phases of mooring adjustment at the start of series are highlighted with caution flags alone.

Documentation is prepared describing the collection, processing and quality of each data series. These are linked to each series to enable standalone use of the data in the future.

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Wyville Thomson Ridge - Ridge Top Mooring Data Activity

This mooring was deployed as part of a long-term monitoring programme examining transport across the Wyville Thomson Ridge.

The instruments were attached to a leaded seasteel mooring with two small glass spheres at the top. The mooring was fitted with an acoustic release which was connected to a chain anchor using L/L chain. The Teledyne ADCP unit was fitted into a 40 inch syntactic sphere with an Argos beacon. The table below indicates the moorings attachments:

The research leading to these results has received funding from NACLIM, a project of the European Union 7th Framework Programme (FP7 2007-2013) under grant agreement n.308299.

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

Wyville Thomson Ridge

The Wyville Thomson Ridge marks the boundary between the Rockall Trough and the Faroe-Shetland Channel. The Ridge is an important area for the study of deep ocean circulation and has been the focus of many studies (particularly CTD surveys), by various institutions, since 1975.

The Wyville Thomson Ridge is also a location of focused mooring activities led by the Scottish Association for Marine Science (SAMS). See Wyville Thomson Ridge Moored ADCP for specific details.

Measurements made along and around the Wyville Thomson Ridge lie within a box bounded by co-ordinates 59° 40' N, 9° 54' W at the southwest corner and 60° 50' N, 5° 00' W at the northeast corner.

Related Fixed Station activities are detailed in Appendix 2

Fixed Station Information

Wyville Thomson Ridge Acoustic Doppler Current Profiler (ADCP) Mooring

Introduction

The Wyville Thomson Ridge is an area of the North Atlantic Ocean floor running in a south easterly direction from the Faroe Bank to the Scottish continental shelf. The most eastern pathway across the Wyville Thomson Ridge marks a noteable boundary between cold and warm deep water at the southern edge of the Faroe-Shetland Channel. To enable monitoring of transport across this region the Scottish Association for Marine Science (SAMS) deployed a succession of Acoustic Doppler Current Profiler (ADCP) moorings (occasionally with auxilliary instrumentation) in the region between 2003 and 2013. These moorings were situated approximately 1.2 km north-west of the formal Faroe end of the Fair Isle-Munken (FIM) line (at approximately 60.2°N, 8.9°W) and constitute part of a larger long term monitoring programme studying the nature of flow across the ridge, and the causes of its variability.

Moored data summary

The following table summarises the SAMS mooring deployments at the Wyville Thomson Ridge:

References

Sherwin, T.J., Griffiths, C.R., Inall, M.E., and Turrell, W.R., 2008. Quantifying the overflow across the Wyville Thomson Ridge into the Rockall Trough, Deep-Sea Research, 55, 4, 396-404.

Related Fixed Station activities are detailed in Appendix 3

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: WTR Ridge Top Mooring Data Activity

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.

Appendix 2: Wyville Thomson Ridge

Related series for this Fixed Station 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.

Appendix 3: Wyville Thomson Ridge Moored ADCP

Related series for this Fixed Station 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.