Metadata Report for BODC Series Reference Number 1208548

• 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 Quality Report

There is clear evidence of mooring 'knockdown' between 23rd November and 29th November 2008 of 20 m for 6 days. This has mostly affected the shallower bins 25-37. The erroneous value -3276.800049 was recorded during this time in the shallower bins, these have been flagged null and set to the absent data value.

Data Access Policy

Public domain 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.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

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

BODC Processing

The data were received in three Matlab format files, one for each instrument. The data were converted into BODC internal format following BODC's standard procedures. The following table shows how the variables within the Matlab file were mapped to appropriate BODC parameter codes. In addition to these, datenumber, instrument_depth, instrument_pressure and pressure accompanied the data but were not transferred.

All reformatted data were visualised using the in-house Edserplo software. All erroneous values of -3276.800049 were set to the absent data value.

Originator's Processing

Data from three Teledyne RDI Workhorse Long-Ranger 75 75kHz ADCPs were collected on three moorings deployed during the SOFINE cruise JC029. During the cruise the data were downloaded and processed into physical units. The ADCP data were viewed in the WinADCP software and inspected for completeness and data quality. The data were then exported to Matlab format.

Project Information

Southern Ocean FINEStructure (SOFINE) project document

The Southern Ocean FINEStructure (SOFINE) project was a UK field programme aimed at studying the frictional processes that slow down the Antarctic Circumpolar Current (ACC) and influence the meridional exchange of water masses in the Southern Ocean.

The study investigated the role of sea floor topography in slowing the ACC and driving meridional flow across the Southern Ocean, and the manner in which mesoscale and small scale oceanic phenomena modified water mass properties and affected their movement across the ACC. Specifically, SOFINE set out to:

• Determine the relative importance of oceanic processes associated with large scale (hundreds to thousands of kilometres) and small scale (a few kilometres) sea floor topography in the context of ACC flow rates and water mass exchange.
• Identify the oceanic processes controlling the rate at which water masses are transformed and fluxed across the ACC.

The SOFINE experiment focused on a major meander of the ACC around the northern Kerguelen Plateau in the Indian Ocean. Theories and models of Southern Ocean circulation indicated that this region experienced intensified 'friction' and cross-ACC flow. Fieldwork was undertaken over a 52 day period in November and December 2008, and included hydrographic observations, microcstructure and turbulence measurements, detailed bathymetric surveys and several deployments of floats, drifters and moorings.

SOFINE was funded by the UK Natural Environment Research Council and involved the collaboration of a number of international institutions: the National Oceanography Centre (UK), the University of East Anglia (UK), British Antarctic Survey (UK), Woods Hole Oceanographic Institution (US), the Commonwealth Scientific and Industrial Research Organisation (Australia), the University of Tasmania (Australia) and the Leibniz Institute of Marine Sciences (IFM-GEOMAR) at the University of Kiel (Germany).

For more information please see the official project website at SOFINE

Data Activity or Cruise Information

Data Activity

SOFINE JC029 Short-term Moored Instrument Eastern Mooring 1

Prior to the mooring operations, a 12 hour swath survey was completed of a ridge that extended northward from the Kerguelen Plateau between -46° 30' S to -47° S and 71.45° E to 72° E. Locations of the mooring sites were then determined from the swath data. Three short-term moorings were deployed located within approximately 1 km of each other. All moorings were deployed using a National Oceanography Centre Southampton (NOCS) double barrel winch (electro-hydraulic) and reeling winch system which was load tested prior to commencement of operations. The moorings were deployed 'top first - anchor last', allowing the buoyancy to stream away from the vessel during deployment. The ship's speed varied between 0.3 and 1.2 knots during the mooring deployment. The anchors for the three UK moorings consisted of a 550 kg mushroom anchor and 2200 kg of eight inch chain. This was designed to be deployed such that as it reached the seabed the mushroom anchor would land first, and the chain would land on the seabed to provide as much scope and drag as possible due to the anticipated high energies.

The mooring location was determined from three independent ranging locations (triangulation) to the acoustic release. The ship was positioned approximately an ocean depth horizontally away from the likely location of the mooring. A transducer was deployed over the side of the ship and the slant range (distance) to the mooring was obtained. The calculated horizontal distance provided an estimate of the radius from the ship location within which the mooring was located. The cross-over of the three range circles ("cocked hat") provided an estimate of the location of the mooring.

Instruments deployed on the rig

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: MOOR1

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.