Metadata Report for BODC Series Reference Number 962449
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
SIMORC data access conditions
The data collated and held at BODC on behalf of the SIMORC project are restricted. However, the data will be available to download from the Official SIMORC Website, as part of the project protocol. The data set will initially include data from the oil companies TOTAL, Shell and BP.
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 20o 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 Current Meter Screening
BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.
Header information is inspected for:
- Irregularities such as unfeasible values
- Inconsistencies between related information. For example:
- Depths of meter and sea bed.
- Times for mooring deployment and for start/end of data series.
- Length of record or number of data cycles, the cycle interval, the clock error and the period over which accrued.
- Parameters stated as measured and the parameters actually present in the data cycles.
- Originator's comments on meter/mooring performance and data quality.
Documents are written by BODC highlighting irregularities which cannot be resolved.
Data cycles are inspected using time series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of adjacent data sets displaced with respect to depth, position or time. Values suspected of being of non- oceanographic origin may be tagged with the BODC flag denoting suspect value.
The following types of irregularity, each relying on visual detection in the time series plot, are amongst those which may be flagged as suspect:
- Spurious data at the start or end of the record.
- Obvious spikes occurring in periods free from meteorological disturbance.
- A sequence of constant values in consecutive data cycles.
If a large percentage of the data is affected by irregularities, deemed abnormal, then instead of flagging the individual suspect values, a caution may be documented. Likewise documents will highlight irregularities seen in the current vector scatter plots such as incongruous centre holes, evidence of mooring 'knock-down', abnormal asymmetry in tidally dominated records or gaps as when a range of speeds or directions go unregistered due to meter malfunction.
The term 'knock-down' refers to the situation when the 'drag' exerted on a mooring at high current speeds may cause instruments to tilt beyond the angle at which they are intended to operate. At this point the efficiency of the current sensors to accurately record the flow is reduced.
Inconsistencies between the characteristics of the data set and those of its neighbours are sought, and where necessary, documented. This covers inconsistencies in the following:
- Maximum and minimum values of parameters (spikes excluded).
- The orientation and symmetry of the current vector scatter plot.
- The direction of rotation of the current vectors.
- The approximate amplitude and periodicity of the tidal currents.
- The occurrence of meteorological events and, finally, for series for which no time check was possible, the phase.
This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.
BODC Processing
Data were received by BODC in an ASCII format file. This was reformatted to QXF format using BODC transfer function 331. The following table shows how the variables within the files were mapped to the appropriate BODC parameter codes:
Original parameter name | Original Units | Description | BODC Parameter Code | BODC Units | Comments |
---|---|---|---|---|---|
Time | DD-MON-YY hh:mm:ss | Date and time (GMT) | AADYAA01 + AAFDZZ01 | Day number and day fraction | Conversion by transfer |
Bin | Metres | Depth bin | DBINAA01 | Metres | |
dirn | Degrees True | Current Direction | LCDAAP01 | Degrees True | |
speed | m/s | Current Speed | LCSAAP01 | cm/s | *100 |
Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO.
Project Information
System of Industry Metocean data for the Offshore and Research Communities (SIMORC)
The EU-funded SIMORC project is a collaborative effort between MARIS (Netherlands), BODC (UK), the International Association of Oil and Gas Producers (OGP) and IOC-IODE to provide a harmonised and quality controlled metocean data set from data collected by oil and gas producers, accessible through the SIMORC protocol.
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 2009-01-17 |
End Date (yyyy-mm-dd) | 2009-07-25 |
Organization Undertaking Activity | Total S.A. |
Country of Organization | France |
Originator's Data Activity Identifier | Louro |
Platform Category | subsurface mooring |
SIMORC Total Louro Current Meter and ADCP mooring.
The survey at this site was made up of a single mooring.
This long mooring was deployed in a water depth of 1832 metres. (Nominal position of 7.504°S 11.2342°E):
Meter No. | Instrument Depth (m) | Instrument Type | Total Time Period | Comments |
---|---|---|---|---|
9771 | 41.2 | RDI 300kHz ADCP | 16-JAN-2009 TO 26-JUL-2009 | Upward-looking. |
677 | 42.7 | SeaBird SBE37 | 16-JAN-2009 TO 26-JUL-2009 | |
11520 | 446.1 | RDI 75kHz ADCP | 16-JAN-2009 TO 26-JUL-2009 | Upward-looking. |
288 | 446.1 | SeaBird SBE39 | 16-JAN-2009 TO 26-JUL-2009 | |
12497 | 696.2 | RCM7 | 16-JAN-2009 TO 26-JUL-2009 | |
11534 | 946.2 | RCM8 | 16-JAN-2009 TO 26-JUL-2009 | |
12474 | 1196.2 | RCM8 | 16-JAN-2009 TO 26-JUL-2009 | |
10050 | 1446.2 | RCM8 | 16-JAN-2009 TO 26-JUL-2009 | |
11260 | 1696.2 | RCM8 | 16-JAN-2009 TO 26-JUL-2009 | |
102 | 1822 | Aanderaa Seaguard | 16-JAN-2009 TO 26-JUL-2009 | with Aanderaa WLR8 |
Related Data Activity activities are detailed in Appendix 1
Cruise
Cruise Name | Seabulk Luanda 2009 |
Departure Date | 2009-01-14 |
Arrival Date | 2009-01-19 |
Principal Scientist(s) | |
Ship | Seabulk Luanda |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
Station Name | Louro, Angola Block 32 |
Category | Offshore location |
Latitude | 7° 30.24' S |
Longitude | 11° 14.05' E |
Water depth below MSL | 1832.0 m |
Total - Angola Block 32 - Louro
Latitude | Longitude | Water depth (m) |
---|---|---|
7.504°S | 11.23417°E | 1829 |
This fixed station is in Block 32, offshore Angola. A mooring was deployed at this site in January 2009 to cover a 12-month period of measurements of currents through the water column. Prior to the mooring deployment, a CTD dip was undertaken to check the actual water depth.
Related Fixed Station activities are detailed in Appendix 2
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 |
Appendix 1: Louro
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.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
1052455 | Offshore sea floor pressure series | 2009-01-17 11:50:00 | 7.504 S, 11.23417 E | Petrogas Supply 1 Petrogas1 |
962450 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962610 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962622 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962634 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962646 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962658 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962671 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
963397 | Hydrography time series at depth | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
963385 | Hydrography time series at depth | 2009-01-17 12:10:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
Appendix 2: Louro, Angola Block 32
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.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
963428 | CTD or STD cast | 2009-01-17 11:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
1052455 | Offshore sea floor pressure series | 2009-01-17 11:50:00 | 7.504 S, 11.23417 E | Petrogas Supply 1 Petrogas1 |
962450 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962610 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962622 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962634 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962646 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962658 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
962671 | Currents -subsurface Eulerian | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
963397 | Hydrography time series at depth | 2009-01-17 12:00:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
963385 | Hydrography time series at depth | 2009-01-17 12:10:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
963441 | CTD or STD cast | 2009-07-25 10:40:00 | 7.504 S, 11.2342 E | Seabulk Luanda Seabulk Luanda 2009 |
1095191 | CTD or STD cast | 2009-07-31 20:32:00 | 7.43115 S, 11.37261 E | Not applicable |
1095178 | CTD or STD cast | 2009-08-01 07:18:00 | 7.48931 S, 11.21687 E | Not applicable |
1095166 | CTD or STD cast | 2009-08-01 09:30:00 | 7.51441 S, 11.22179 E | Not applicable |
1095209 | CTD or STD cast | 2009-08-01 12:47:00 | 7.50099 S, 11.26061 E | Not applicable |