Metadata Report for BODC Series Reference Number 756718
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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Problem Reports
The originator reported that the data return was reduced for several days due to a combination of exceedence of the Data Storage Unit (DSU) memory capacity.
Data Quality Report NIGERIARCM741MP2
There are no data from 17/01/2005 10:20.
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
Aanderaa Recording Current Meter Model 7/8
Manufacturer's specifications: recording unit height 49.5cm (RCM8 52.0cm), diameter 12.8cm, vane size 48.5x50.0cm. Meter is designed for depths down to 2000m (RCM8 6000m). It incorporates a spindle which is shackled to the mooring line. The meter is attached to the spindle through a gimbal mounting which permits a maximum 27° deviation of the spindle from the vertical, the meter still remaining horizontal.
Meter comprises :
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Paddle wheel rotor magnetically coupled to an electronic counter
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Vane, which aligns instrument with current flow, has a balance weight ensuring static balance and tail fins to ensure dynamic balance in flows up to 250cm/s.
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Magnetic compass (needle is clamped to potentiometer ring) - direction recorded with 0.35° resolution, 5° accuracy for speeds 5 to 100cm/s, 7.5° accuracy for remaining speeds within 2.5 to 200cm/s range.
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Quartz clock, accuracy better than 2 sec/day within temperature range 0 to 20°C.
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Thermistor (temperature sensor), standard range -2.46 to 21.48°C (max on high range 36.04°C), accuracy 0.05°C, resolution 0.1 per cent of range, 63 per cent response time 12sec.
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Inductive cell conductivity sensor (optional), range 0 to 70mmho/cm standard resolution 0.1 per cent of range.
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Silicon piezoresistive bridge, standard range 0 to 3000 psi (RCM8 to 9000 psi), resolution 0.1% of range.
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Self balancing potentiometer which converts the output from each sensor into a 10 bit binary number for storage on magnetic tape.
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Associated electronics.
A built-in clock triggers the instrument at preset intervals and up to six channels are sampled in sequence. Channel 1 is a fixed reference reading for control purposes and data identification. Channels 2, 3 and 4 represent measurement of temperature, conductivity and pressure. Channels 5 and 6 represent the VECTOR AVERAGED current speed and direction since the previous triggering of the instrument. The number of rotor revolutions and the direction is sampled every 12 seconds and broken into North and East components. Successive components are added and recorded as speed and direction. For recording intervals longer than 10 minutes, speed and direction are sampled 1/50th of recording interval.
It has become common practice in some laboratories to deploy these meters as temperature and conductivity loggers without current measuring capabilities.
The following link will provide the manufacturer specifications:
Manufacturer specificationsBODC 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 ASCII format files. The originator provided concatenated data from 3 different instruments (RCM at -33m, Long Ranger ADCP at -741m and a Workhorse ADCP at -490m). BODC split these concatenated files into Matlab format files per instrument as following:
Originator data files | Files used for transfer |
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PHASE1.TXT | NigeriaWHADCP33mP1.mat, NigeriaRCM741mP1.mat and NigeriaLRADCP490mP1.mat |
PHASE2.TXT | NigeriaWHADCP33mP2.mat, NigeriaRCM741mP2.mat, NigeriaLRADCP490mP2.mat |
PHASE3.TXT | NigeriaRCM741mP3.mat, NigeriaLRADCP490mP3.mat, NigeriaWHADCP33mP3.mat |
These Matlab format files 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 |
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SPEED | m.s-1 | 10-minute vector average | LCSAEL01 | cm.s-1 | Conversion (RAW * 100) by transfer |
DIRN | degrees true | 10-minute vector average | LCDAEL01 | 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'.
The originator provided current meter data in Phase 3 but the data were not transferred because the channel was null.
Originator processing notes
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.
- Inspection of the quality of water level, temperature data by an experienced oceanographer to identify and remove any remaining anomalous values.
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 |
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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 |
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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 |
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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 |
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762423 | Currents -subsurface Eulerian | 2004-09-05 19:00:00 | 3.50297 N, 7.4953 E | Not applicable |
762459 | 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 |
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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 |
762423 | Currents -subsurface Eulerian | 2004-09-05 19:00:00 | 3.50297 N, 7.4953 E | Not applicable |
762459 | 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 |