Metadata Report for BODC Series Reference Number 1029968

• 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

No Problem Report Found in the Database

SIMORC Total Indonesia moored CTD Data Narrative

Narrative

RBR Ltd XR420 marine CTDs - were deployed on the Sisi, Stupa, Peciko and Tunu 1,2 and 3 moorings, Indonesia.

Data Quality Information

The following data quality checks were applied

• Density of sensors from the same moorings was checked to confirm that the shallowest deployed sensor recorded a lower or equal density to the deeper.
• Changes in temperature, salinity, density and sound speed too large to be physically feasible were flagged suspect.

The data from the top CTDs at the Sisi site showed salinity, sound velocity and density values which gradually decreased from the beginning of the mooring deployment until the end, interspersed with a number of sudden upward shifts in all these parameters. These occurred on 1st March 2008, 6th April 2008, June 26th 2008, July 18th 2008, November 24th 2008. This data should therefore be used with caution.

The density data from the 2 Peciko moored CTDs occasionally showed more dense water at the top sensor (15 metres depth) than the bottom sensor (41 metres depth). This data should therefore be used with caution.

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

RBR XR-420 CTD

The XR-420 CTD Marine is a small, autonomous conductivity, temperature and depth recorder, from which high accuracy speed of sound and salinity can be derived. Its titanium housing provides a depth rating for the cell of 6,600m which can be axial to the logger, whilst also providing shielding and stable cell geometry. The normal marine conductivity range of 0 to 70 mS/cm is measured by an inductive cell to an accuracy of ±0.003 mS/cm and with a response time of less than 95 milliseconds when profiling. It uses a three-coil system with a closed loop feedback for superior temperature compensation. 8MB of nonvolatile flash memory allows for 2, 400, 000 readings which can be logged on one set of high-powered 3V lithium batteries

Specifications

Further information can be found on the Official RBR Website or in the manufacturer's specification sheet.

BODC Processing

Data were received by BODC in CSV files. They were then reformatted to QXF format using BODC transfer function 422. The following table shows how the variables within the files were mapped to the appropriate BODC parameter codes:

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

Originator's Data Processing

Data processing

Conductivity and temperature data were exported from RBR Ltd software, for the following processing:

• The record was truncated to exclude times pre and post deployment.
• Time was recorded in GMT.
• Salinity was calculated according to the UNESCO 1978 algorithm.
• Depth was derived using an assumed gravity constant of 9.8 m.s^-1 and an assumed water density of 1024 kg.m^-3
• Density was then derived from the salinity and temperature data according to the UNESCO 1980 Equation of State.
• Sound velocity was calculated from the salinity, temperature and pressure data using the UNESCO 1983 algorithm of Fofonoff and Millard.

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.

Data Activity or Cruise Information

Data Activity

SIMORC Mooring Station Indonesia Stupa

The position of the mooring was 1.4802° S; 117.0113° E at a depth of 54 metres.

The mooring was deployed on behalf of TOTAL at Stupa, Indonesia and consisted of the following instruments.

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

SIMORC: TOTAL Indonesia Stupa Fixed Station Document

This site is offshore of the Mahakam Delta, north of Balikpapan in the Makassar Strait. A mooring was deployed at this site.

The nominal position of this site is 1.4802° S; 117.0113° E with an approximate water depth of 60 metres.

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: Stupa

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: Indonesia Stupa

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.