Metadata Report for BODC Series Reference Number 1722479
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
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Time Co-ordinates(UT) |
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Parameters |
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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
Instrument Description
The LADCP data were collected using the instrumentation detailed below:
| Sensor | Model | Serial Number | Calibration (UT) | Comments |
|---|---|---|---|---|
| LADCP | Teledyne RDI high-power Workhorse 300kHz | 15288 | - | LDEO unit, downward looking |
One Teledyne RDI Workhorse 300kHz ADCP was mounted on the Sea-Bird 9 11 plus CTD frame pointing downward (downlooker).
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 Processing
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 after discussion with the originator. All data provided were from the downward looking RDI 300 kHz Workhorse 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:
| Originator's Parameter Name | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| z | m | Depth of LADCP bin | ADEPZZ01 | m | - |
| u | m s-1 | Eastward velocity | LCEWLW01 | cm s-1 | Units converted from m s-1 to cm s-1 by multiplying by 100. |
| v | m s-1 | Northward velocity | LCNSLW01 | cm s-1 | Units converted from m s-1 to cm s-1 by multiplying by 100. |
| ev | m s-1 | Uncertainty estimates of LADCP velocity profile | ERRVLDCP | cm s-1 | Units converted from m s-1 to cm s-1 by multiplying by 100. |
All reformatted data were visualised using the in-house Edserplo software. Suspect and missing data were marked by adding an appropriate quality control flag.
Note that the more complex LDEO processed data are available on request in Matlab format as well as the unprocessed raw LADCP files.
Originator's Data Processing
Sampling Strategy
A total of 84 LADCP profiles were collected at all CTD stations in order to derive full-depth profiles of ocean velocity, as well as profiles of finestructure vertical shear.
Data processing
Preliminary shipboard processing of the LADCP data was carried out with the LDEO IX LADCP processing software using averaged one Hz ascii CTD data in order to correct the LADCP data for depth and sound speed.
Please refer to Thurnherr (2014) and cruise report for a more detailed processing methodology. However, please be aware that this processing guide is for software versions IX.7 to IX.10 only, and changes have been made between versions which have the potential for significantly changing the solutions.
References
Thurnherr, A. M., 2014. How To Process LADCP Data With the LDEO Software, Versions IX.7 - IX.10.
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Cruise
| Cruise Name | DY031 |
| Departure Date | 2015-05-29 |
| Arrival Date | 2015-06-17 |
| Principal Scientist(s) | N Penny Holliday (National Oceanography Centre, Southampton) |
| Ship | RRS Discovery |
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:
| Flag | Description |
|---|---|
| Blank | Unqualified |
| < | Below detection limit |
| > | In excess of quoted value |
| A | Taxonomic flag for affinis (aff.) |
| B | Beginning of CTD Down/Up Cast |
| C | Taxonomic flag for confer (cf.) |
| D | Thermometric depth |
| E | End of CTD Down/Up Cast |
| G | Non-taxonomic biological characteristic uncertainty |
| H | Extrapolated value |
| I | Taxonomic flag for single species (sp.) |
| K | Improbable value - unknown quality control source |
| L | Improbable value - originator's quality control |
| M | Improbable value - BODC quality control |
| N | Null value |
| O | Improbable value - user quality control |
| P | Trace/calm |
| Q | Indeterminate |
| R | Replacement value |
| S | Estimated value |
| T | Interpolated value |
| U | Uncalibrated |
| W | Control value |
| X | Excessive difference |
SeaDataNet Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
| Flag | Description |
|---|---|
| 0 | no quality control |
| 1 | good value |
| 2 | probably good value |
| 3 | probably bad value |
| 4 | bad value |
| 5 | changed value |
| 6 | value below detection |
| 7 | value in excess |
| 8 | interpolated value |
| 9 | missing value |
| A | value phenomenon uncertain |
| B | nominal value |
| Q | value below limit of quantification |
