Metadata Report for BODC Series Reference Number 1920008

• 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

BODC Data Quality Report

No flags were applied to JR20140308 or JR20140331 LADCP data during screening.

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

Teledyne RDI's Workhorse Monitor ADCP

The Workhorse Monitor acoustic doppler current profler (Teledyne RD Instruments) is a long-range and long-term self contained ADCP. It has a patented four beam signal (300, 600 or 1200 kHz) and a standard depth rating of 200m or 600m. It operates effectively between temperatures of -5°C and 45°C and has a velocity accuracy of ±1% ±5mm/s.

BODC Data Processing

Lamont-Doherty Earth Observatory (LDEO) processed data were provided by the originator in Matlab and ASCII formats. The LDEO processed data in ASCII format were converted into BODC internal format following discussion with the originator. All data provided were from the downward looking Teledyne RDI Workhorse 300 kHz ADCP, which was in operation at the time. The following table shows how the variables within the ASCII files were mapped to appropriate BODC parameter codes:

All reformatted data were visualised using the in-house Edserplo software. Suspect and missing data were marked by adding an appropriate quality control flag.

The unprocessed raw LADCP files and the more complex LDEO processed data, in Matlab format, are available on request. Further information on the originator's quality control on the more complex LDEO processed data can be found in the originator's quality control report.

Originator's Data Processing

Instrument description

Two Teledyne RDI Workhorse 300 kHz instruments were mounted on a CTD frame, a downlooker/master (serial number 15060) and an uplooker/slave (serial number 14897).

Sampling strategy

Lowered Acoustic Doppler Current Profiler (LADCP) profiles were attempted at all CTD stations (1 - 119) in order to derive full-depth profiles of ocean velocity, as well as profiles of finescale vertical shear of horizontal velocities. Leg 2 of JR299 includes CTD stations 33 - 119 (87 LADCP profiles).

Data processing

During the cruise, the quality of the JR299 LADCP data was remotely monitored at Lamont-Doherty Earth Observatory (LDEO). All diagnostic plots created during shipboard processing were inspected and suspicious profiles flagged. Preliminary processing was completed using the LDEO LADCP software version IX_6. Range corrections were made using sound speed profiles calculated from the CTD data for each station.

Post cruise, all profiles were re-processed following the same method as on the ship with the most up-to-date version of the LDEO software (IX_11beta). Please refer to the data quality report, cruise report and Thurnherr (2014) for more details about the processing methodology.

References

Thurnherr, A. M., 2014. How To Process LADCP Data With the LDEO Software, Versions IX.7 to IX.10.

Project Information

Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) project document

DIMES is a US/UK field program aimed at measuring diapycnal and isopycnal mixing in the Southern Ocean, along the tilting isopycnals of the Antarctic Circumpolar Current.

The Meridional Overturning Circulation (MOC) of the ocean is a critical regulator of the Earth's climate processes. Climate models are highly sensitive to the representation of mixing processes in the southern limb of the MOC, within the Southern Ocean, although the lack of extensive in situ observations of Southern Ocean mixing processes has made evaluation of mixing somewhat difficult. Theories and models of the Southern Ocean circulation have been built on the premise of adiabatic flow in the ocean interior, with diabatic processes confined to the upper-ocean mixed layer. Interior diapycnal mixing has often been assumed to be small, but a few recent studies have suggested that diapycnal mixing might be large in some locations, particularly over rough bathymetry. Depending on its extent, this interior diapycnal mixing could significantly affect the overall energetics and property balances for the Southern Ocean and in turn for the global ocean. The goals of DIMES are to obtain measurements that will help us quantify both along-isopycnal eddy-driven mixing and cross-isopycnal interior mixing.

DIMES includes tracer release, isopycnal following RAFOS floats, microstructure measurements, shearmeter floats, EM-APEX floats, a mooring array in Drake Passage, hydrographic observations, inverse modeling, and analysis of altimetry and numerical model output.

DIMES is sponsored by the National Science Foundation (U.S.), Natural Environment Research Council (U.K) and British Antarctic Survey (U.K.)

For more information please see the official project website at DIMES

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

North Scotia Ridge Hydrographic Section

The North Scotia Ridge Section (NSR) is a repeat hydrographic section along the ridge crest of the North Scotia Ridge running between the Falklands and South Georgia. The nominal end points of the section (to date) are 53° 57.256' S, 39° 38.702' W and 54° 23.653' S, 55° 40.552' W. It was first occupied in 2014 as part of the DIMES tracer release experiment (RRS James Clarke Ross cruise JR299) and has been repeated by the ORCHESTRA project (RRS Discovery cruise DY113) in 2020.

A table of cruises which occupied the NSR is presented below with links to the relevant cruise reports.

Related Fixed Station activities are detailed in Appendix 1

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: North Scotia Ridge Section - NSR

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.