Metadata Report for BODC Series Reference Number 746761

• 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

The originator reports that the direction data are not valid from 00:00:01 01/05/2002 to 23:59:59 31/05/2003, these data were accordingly flagged 'L'.

SIMORC Data Quality Report: Angola Block 17 Wind Data DAT2003_03

Wind directions are reported as not valid from May 2002 - May 2003. Speed data appear of good quality. There are gaps on the following dates: 2,3,9 March 2003; 10-20 March 2003, 20 March 2003; 21, 22 March 2003.

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

VAISALA Wind Sensor Model QMW110

The Vaisala Combined Wind Sensor monitors both wind speed and direction with excellent linearity and fast response. A single compact sensor, it is ideal for low-power applications. Wind direction is detected using an axial symmetric rotating potentiometer with two slides, which provides full coverage from 0 to 360°.

Technical information

Anemometer

Measurement range: 0.5 to 60 m/s

Performance (accuracy): + 0.3 m/s (< 10 m/s), < 2 % (> 10 m/s)

Threshold: 0.5 m/s

Distance constant: 2 m

Wind vane

Measurement range: 0 to 360°

Performance (accuracy): < ± 3°

Threshold: < 1.0 m/s

Delay distance: 1.0

Operating temperature range: -40 to +55 °C

Dimensions: 265 x 360 mm

Weight: 360 g

Cable length: QMW101 - 1 m, QMW110 - 10 m

Manufacturer's specification

BODC Processing

Data were received by BODC in ASCII format files. These were reformatted to the internal QXF format using BODC transfer function 407. The following table shows how the variables within the file were mapped to the appropriate BODC parameter codes:

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO.

General Data Screening carried out by BODC

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:
  • Times for instrument deployment and for start/end of data series
  • Length of record and the number of data cycles/cycle interval
  • Parameters expected 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 or depth 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 data values will not be altered.

The following types of irregularity, each relying on visual detection in the 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 then a Problem Report will be written rather than flagging the individual suspect values. Problem Reports are also used to highlight irregularities seen in the graphical data presentations.

Inconsistencies between the characteristics of the data set and those of its neighbours are sought and, where necessary, documented. This covers inconsistencies such as the following:

• Maximum and minimum values of parameters (spikes excluded).
• The occurrence of meteorological events.

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.

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.

ELF EXPLORATION ANGOLA, offshore ocean monitoring, Block 17

ELF ANGOLA required ocean monitoring services from March 2001 to July 2004. MeteoMer measured the following parameters :

• Waves (Directional Datawell waverider)
• Motion of the Floating Production, Storage and Offloading (FPSO) vessel (Hippy 80 - Datawell)
• Motion of the Single Buoy Mooring (Hippy 80 - Datawell)
• Wind of the FPSO (VAISALA Marine Automated Weather Station)
• Current profiles (ADCP RDI 300 khz and 75 khz)

Data Activity or Cruise Information

Data Activity

SIMORC: TOTAL Data, Angola, Block 17, Wind Survey Data Activity

This site is part of the Total facility.

The generic position of the site is 7.7 °S, 11.667 °E with a water depth of 1000 m.

The wind data have been collected by Meteomer-Actimar on behalf of Total using a meteorological station on the Floating Production, Storage and Offloading vessel Girassol, 60m above MSL, in the Angola Block 17 Girassol as follows.

Related Data Activity activities are detailed in Appendix 1

Fixed Station Information

Fixed Station Information

SIMORC: Total Angola, Block 17 Girassol, Fixed Station Document

This site is part of the Total facility.

The moorings deployed lie within a box bounded by co-ordinates 7.7° S, 11.65° E at the southwest corner and 7.67° S, 11.6825° E at the northeast corner.

The GIRASSOL platform, Block 17, offshore Angola consists of a Floating Production, Storage and Offloading vessel (FPSO) and a Single Buoy Mooring (SBM).

Various deployments were taken from or near this station over a number of years.

Between September 1997 and October 1998

A current meter mooring occupied this site. In addition to time series data obtained from the moored instruments, CTD profiles were conducted following the deployment and prior to the recovery of the mooring to be used for calibration purposes.

Between March 2001 and July 2004

Wind, current and wave data have been collected on behalf of Total on the Girassol field.

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:

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: SIMORC: TTL Data, Angola, Block 17, Wind

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.

Appendix 2: ANGOLA GIRASSOL

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.