Metadata Report for BODC Series Reference Number 1209945

• 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 which has effected all instruments particularly the RBR_10822 from Mooring 2 (BODC series identifier 1209933).

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

RBR XR-420 CTD

The XR-420 CTD Marine is a small, autonomous conductivity, temperature and depth recorder, from which high accuracy speed of sound and salinity can be derived. Its titanium housing provides a depth rating for the cell of 6,600m which can be axial to the logger, whilst also providing shielding and stable cell geometry. The normal marine conductivity range of 0 to 70 mS/cm is measured by an inductive cell to an accuracy of ±0.003 mS/cm and with a response time of less than 95 milliseconds when profiling. It uses a three-coil system with a closed loop feedback for superior temperature compensation. 8MB of nonvolatile flash memory allows for 2, 400, 000 readings which can be logged on one set of high-powered 3V lithium batteries

Specifications

Further information can be found on the Official RBR Website or in the manufacturer's specification sheet.

BODC Processing

The data were received in four Matlab format files one for each instrument, no data were received for instrument number 17027. The received 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, time and datenum accompanied the data but were not transferred.

All reformatted data were visualised using the in-house Edserplo software. Suspect and missing data were marked by adding an appropriate quality control flag. Data were flagged at the beginning and end of the series to cover the deployment and recovery.

References

Fofonoff, NP and Millard, RC. 1983. Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science, 44, p.53.

Originator's Processing

Data from five RBR XR-420 CTD Marine instruments were collected on three moorings deployed during the SOFINE cruise JC029. During the cruise the data were downloaded and processed into physical units. The downloaded data was inspected for completeness and data quality. As part of this process, data from the instrument were stored in the form of a Matlab structure.

The instrument RBR XR-CTD S/N 17027 from the eastern mooring 1 failed. The instrument leaked at the sensor (possibly temperature) end and water drained to the battery end bottom down causing damage. Both end O-rings were inspected and looked fine. There was no data retrieval from this instrument.

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 Central Mooring 3

Prior to the mooring operations, a 12 hour swath survey of a ridge that extended northward from the Kerguelen Plateau between-46° 30' S to -47° S and 71° 45' E to 72° E was completed. 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: MOOR3

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.