Metadata Report for BODC Series Reference Number 762459
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
RD Instruments 300kHz Workhorse Sentinel Acoustic Doppler Current Profiler
Specifications
Water velocity measurements relative to the ADCP | |
---|---|
Maximum velocity | 10 m.s-1 |
Standard deviation | 130, 45, 25, 12, 5 mm.s-1 for depth cell sizes of 1, 2, 4, 8, 16 m, respectively |
Minimum time between pings | 0.07 s |
Maximum profiling range* | 110, 120, 130, 150, 165 m for depth cell sizes of 1, 2, 4, 8, 16 m, respectively |
Minimum range to start of first depth cell | 3 m |
Number of depth cells | 1 - 128 cells |
Depth cell size | 1 - 16 cm |
Echo Intensity measurements | |
Uncertainty | ± 1.5 dB |
Sampling | Uses same depth cells and time intervals as velocity |
Sensors | |
Water level resolution | 0.25 m |
Water level accuracy | ± 5 m over 0-200 m depth |
Temperature range | -5°C to + 45°C |
Temperature uncertainty | ± 0.4°C |
Tilt range | ± 20° |
Tilt uncertainty | ± 2° |
Compass uncertainty | ± 5° at 60° magnetic dip angle |
Compass maximum tilt | 20° |
Physical and Environmental | |
Maximum depth | 200 m |
Operating temperature | -5°C to 60°C |
Storage Temperature | -5°C to 80°C |
The manufacturer's specification document can be found here
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 in ASCII format files. These series were reformatted to the internal QXF format using BODC transfer function 415. The following table shows how the variables within the file were mapped to the appropriate BODC parameter codes:
Original parameter name | Original Units | Description | BODC Parameter Code | BODC Units | Comments |
---|---|---|---|---|---|
Time | DD/MM/YYYY HH:MI GMT | Date and time | AADYAA01 + AAFDZZ01 | day number and day fraction GMT | Conversion by transfer |
SPEED | m.s-1 | Current speed | LCSAAP01 | cm.s-1 | Conversion (RAW * 100) by transfer |
DIRN | degrees true | Current direction | LCDAAP01 | degrees true |
Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'.
Nigeria Usan ADCP processing
The originator reported the following processing notes:
Data were transferred to the Fugro GEOS Alpha server for quality control, processing and analysis. Quality control procedures applied during post-processing included, but were not limited to the following:
- Production of quality control plots to assess the general quality of the data and evaluate the effectiveness of each individual quality control procedure.
- Error flagging of records with current speeds beyond extreme limits and exceeding quality control parameter thresholds carried out on all data from all measurement depths.
- Application of the magnetic declination of -3.3° E.
- Inspection of the quality of current, wave, water level, temperature and salinity data by an experienced oceanographer to identify and remove any remaining anomalous values.
There was some evidence of biological interference in the ADCP current velocity data from both the Workhorse and Long Ranger instruments, which was removed from the final data sets by manual editing. The biological interference was identified in the vertical velocity and echo amplitude records from the instruments. Elevated values of these parameters corresponded to dawn and dusk migrations of zooplankton. Whilst care has been taken to remove all such erroneous data, it is possible that other data records remain which have been influenced in some way by acoustic scatterer movement.
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) | 2004-09-05 |
End Date (yyyy-mm-dd) | 2005-01-20 |
Organization Undertaking Activity | Total S.A. |
Country of Organization | France |
Originator's Data Activity Identifier | OPL222#2 |
Platform Category | subsurface mooring |
SIMORC Moored Instrument OPL222#2
The generic position of this site is 03° 30.229' N, 007° 29.683' E with a water depth of 743 m.
3 moorings consisting of 2 ADCP, 1 current meter and 1 water level recorder were deployed from a subsurface mooring.
This particular mooring was deployed on 5/09/2004 and was removed on 20/01/2005. This current mooring was set on behalf of TOTAL in Nigeria, OPL 222 Usan and consisted of the following series.
Depth (m) | Instrument type | Serial Number | Deployment start | Deployment end | Comments |
---|---|---|---|---|---|
37 | 300 kHz Workhorse ADCP | 328 | 05/09/2004 19:00 | 20/01/2005 15:30 | Current and wave data were recorded. |
496 | 75 kHz Long Ranger ADCP | 1430 | 05/09/2004 19:00 | 20/01/2005 15:30 | |
740 | Aanderaa RCM 7 | 10737 | 05/09/2004 19:00 | 20/01/2005 15:30 | |
741 | Aanderaa WLR 8 | 1793 | 05/09/2004 20:20 | 04/12/2004 00:30 |
Related Data Activity activities are detailed in Appendix 1
Fixed Station Information
Fixed Station Information
Station Name | Nigeria OPL 222 Usan |
Category | Offshore location |
Latitude | 3° 30.18' N |
Longitude | 7° 29.69' E |
Water depth below MSL | 746.0 m |
Nigeria OPL 222 Usan Fixed Station Document
On behalf of Elf Petroleum Nigeria Ltd, Fugro Global Environmental and Oceanographic Sciences has undertaken a one-year program of deep water oceanographic measurements in Block OPL222.
A single mooring was deployed, comprising oceanographic instrumentation measuring current speed and direction data throughout the water column, wave height and period, water level elevation and seawater temperature data.
A CTD profiler was deployed and recovered prior to both the mooring deployment and recovery to measure temperature and salinity profiles throughout the water column and verify the water depth.
The moorings deployed lie within a box bounded by co-ordinates 3.300715° N, 7.00628° E at the southwest corner and 3.60702° N, 7.52° E at the northeast corner.
Meteocean data have been collected on behalf of Total from the OPL 222 Usan Station as follows:
Rig / Instrument Identification | Meter Type | Start Date | End Date | Comments |
---|---|---|---|---|
OPL222#1 | ADCP | 30/05/2004 | 04/09/2004 | Current and wave data were recorded. |
OPL222#1 | CM | 30/05/2004 | 04/09/2004 | |
OPL222#1 | WLR | 30/05/2004 | 27/08/2004 | |
OPL222#2 | ADCP | 05/09/2004 | 20/01/2005 | Current and wave data were recorded. |
OPL222#2 | CM | 05/09/2004 | 20/01/2005 | |
OPL222#2 | WLR | 05/09/2004 | 04/12/2004 | |
OPL222#3 | ADCP | 22/01/2005 | 03/06/2005 | Current and wave data were recorded. |
OPL222#3 | CM | 22/01/2005 | 03/06/2005 | RCM flooded and provided no data. |
OPL222#3 | WLR | 22/01/2005 | 22/04/2005 |
21 CTD casts were taken from 21/06/2004 to 04/07/2004.
Where
- ADCP = Acoustic Doppler Current Profiler
- CM = Current Meter
- CTD = Pressure, temperature and conductivity profiler
- WLR = Water Level Recorder
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: OPL222#2
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 |
---|---|---|---|---|
756718 | Currents -subsurface Eulerian | 2004-09-05 19:00:00 | 3.503 N, 7.49533 E | Not applicable |
762423 | Currents -subsurface Eulerian | 2004-09-05 19:00:00 | 3.50297 N, 7.4953 E | Not applicable |
962382 | Sea surface elevation -unspecified | 2004-09-05 20:20:00 | 3.50297 N, 7.4953 E | Not applicable |
Appendix 2: Nigeria OPL 222 Usan
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 |
---|---|---|---|---|
756706 | Currents -subsurface Eulerian | 2004-05-30 11:30:00 | 3.50383 N, 7.49467 E | Not applicable |
762411 | Currents -subsurface Eulerian | 2004-05-30 11:30:00 | 3.50382 N, 7.49472 E | Not applicable |
762447 | Currents -subsurface Eulerian | 2004-05-30 11:30:00 | 3.50382 N, 7.49472 E | Not applicable |
962370 | Sea surface elevation -unspecified | 2004-05-30 12:30:00 | 3.50382 N, 7.49472 E | Not applicable |
941052 | CTD or STD cast | 2004-05-30 15:49:00 | 3.50308 N, 7.49488 E | Akademik Golitsin 2004 |
941107 | Bathythermograph -expendable | 2004-06-21 04:22:00 | 3.5725 N, 7.37868 E | Rig Supporter 2004 1/13 |
941039 | CTD or STD cast | 2004-06-21 11:33:00 | 3.00715 N, 7.00628 E | Rig Supporter 2004 1/13 |
941119 | Bathythermograph -expendable | 2004-06-21 18:11:00 | 3.4292 N, 7.37717 E | Rig Supporter 2004 1/13 |
941120 | Bathythermograph -expendable | 2004-06-22 03:30:00 | 3.4845 N, 7.43642 E | Rig Supporter 2004 2/13 |
941132 | Bathythermograph -expendable | 2004-06-22 23:22:00 | 3.50618 N, 7.45377 E | Rig Supporter 2004 2/13 |
941144 | Bathythermograph -expendable | 2004-06-23 11:45:00 | 3.4576 N, 7.39457 E | Rig Supporter 2004 3/13 |
941156 | Bathythermograph -expendable | 2004-06-23 19:51:00 | 3.4704 N, 7.40398 E | Rig Supporter 2004 3/13 |
941168 | Bathythermograph -expendable | 2004-06-24 05:22:00 | 3.54 N, 7.47707 E | Rig Supporter 2004 4/13 |
941181 | Bathythermograph -expendable | 2004-06-25 08:11:00 | 3.43525 N, 7.3481 E | Rig Supporter 2004 5/13 |
941193 | Bathythermograph -expendable | 2004-06-25 19:07:00 | 3.56788 N, 7.52 E | Rig Supporter 2004 5/13 |
941200 | Bathythermograph -expendable | 2004-06-26 04:29:00 | 3.5704 N, 7.48732 E | Rig Supporter 2004 6/13 |
941212 | Bathythermograph -expendable | 2004-06-27 07:05:00 | 3.47013 N, 7.36078 E | Rig Supporter 2004 7/13 |
941224 | Bathythermograph -expendable | 2004-06-27 19:00:00 | 3.48072 N, 7.3724 E | Rig Supporter 2004 7/13 |
941040 | CTD or STD cast | 2004-06-29 18:51:00 | 3.53808 N, 7.48333 E | Rig Supporter 2004 8/13 |
941236 | Bathythermograph -expendable | 2004-06-30 08:03:00 | 3.60702 N, 7.44528 E | Rig Supporter 2004 9/13 |
941248 | Bathythermograph -expendable | 2004-07-01 08:03:00 | 3.45983 N, 7.3237 E | Rig Supporter 2004 10/13 |
941261 | Bathythermograph -expendable | 2004-07-02 08:43:00 | 3.4956 N, 7.34248 E | Rig Supporter 2004 11/13 |
941273 | Bathythermograph -expendable | 2004-07-02 21:59:00 | 3.49035 N, 7.32445 E | Rig Supporter 2004 11/13 |
941285 | Bathythermograph -expendable | 2004-07-03 23:14:00 | 3.53367 N, 7.34938 E | Rig Supporter 2004 12/13 |
941297 | Bathythermograph -expendable | 2004-07-04 05:22:00 | 3.59038 N, 7.4052 E | Rig Supporter 2004 13/13 |
941304 | Bathythermograph -expendable | 2004-07-04 19:58:00 | 3.59338 N, 7.39247 E | Rig Supporter 2004 13/13 |
941064 | CTD or STD cast | 2004-09-04 10:26:00 | 3.50308 N, 7.49488 E | HD Inspector 2004 |
756718 | Currents -subsurface Eulerian | 2004-09-05 19:00:00 | 3.503 N, 7.49533 E | Not applicable |
762423 | Currents -subsurface Eulerian | 2004-09-05 19:00:00 | 3.50297 N, 7.4953 E | Not applicable |
962382 | Sea surface elevation -unspecified | 2004-09-05 20:20:00 | 3.50297 N, 7.4953 E | Not applicable |
941076 | CTD or STD cast | 2005-01-22 13:08:00 | 3.50308 N, 7.49488 E | HD Inspector 2005 |
762435 | Currents -subsurface Eulerian | 2005-01-22 21:00:00 | 3.50248 N, 7.49463 E | Not applicable |
762460 | Currents -subsurface Eulerian | 2005-01-22 21:00:00 | 3.50248 N, 7.49463 E | Not applicable |
962394 | Sea surface elevation -unspecified | 2005-01-22 21:00:00 | 3.50248 N, 7.49463 E | Not applicable |
941088 | CTD or STD cast | 2005-06-03 05:28:00 | 3.50308 N, 7.49488 E | Smit-Lloyd 72 2005 |