Metadata Report for BODC Series Reference Number 1748556

• 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

Quality report - iSTAR Moorings

It is clear from data from pressure sensors (and other sensors measuring the orientation of instruments on the mooring) that the iSTAR moorings were occasionally displaced in the water column. Given the location of the mooring it is likely that this disruption was caused by ice bergs knocking in to the mooring array. This was particularly noticeable in the data from moorings iSTAR6 (where the array became ~ 60m deeper on 05 January 2013), iSTAR9 (where the array became ~ 10 m deeper between 14 and 17 November 2013) and PIG_S (where the array became ~ 50 m deeper on the 20 July 2014 and then ~50 m deeper again on 30 July 2015).

Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

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 20^o 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 Processing - iSTAR Moored RDI ADCP

Data were received by BODC in Matlab files, with one file containing all data from an iSTAR mooring array. The data were reformatted to QXF (a NetCDF file format) by in house software. A separate QXF file was created for data from each instrument. Metadata were also extracted from the originator's file and used to populate the BODC database.

The following tables shows how the variables within the files were mapped to appropriate BODC parameter codes:

Due to the volume of data supplied the datasets have been stored as yearly files (so a mooring that was deployed in 2012 and recovered in 2014 will have been split in to three datasets).

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

Originator's processing - iSTAR Moored RDI ADCPs

Data processing

The originator calibrated data from the moorings with data from CTD casts taken at deployment and recovery. Instrument depths have been corrected based on pressure data from adjacent instruments. Corrections have not been made for speed of sound, as these corrections were estimated by the originator to be insignificant. Where appropriate temperature and pressure offsets were applied (these are documented in the table below.

The magnetic variation calculated from the International Geomagnetic Reference Field (IGRF) at each mooring position on 01 January 2013 was recorded. The following variables had magnetic variation corrections applied by the originator:

• current direction
• northward component of current
• eastward component of current

Magnetic variation corrections weren't applied to heading

The full data from ADCP s/n 15460 on iSTAR7 have not been ingested by BODC, because of the large amounts of data this instrument recorded. The data in the file supplied by the originator that BODC ingested are the averages of each hourly four-minute burst (of 120 ensembles, each containing four 2-Hz pings).

Offsets applied

Echo intensity coefficients

The echo intensity data were provided to BODC by the originator with units of counts. This unit is a proprietary unit, but it is proportional to decibels (dB). The manufacturer has supplied coefficients for each ADCP and each beam (Kc coefficient) which can be used to calibrate and convert the echo intensity from units of Count to units of dB. BODC has not applied these coefficients, but they are available in the table below (so that an end-user can decide what is best for their processing needs).

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

iSTAR1 Mooring

iSTAR1 is a mooring array deployed for the iSTAR programme. The mooring was deployed from RV Araon in March 2012 and recovered from RRS James Clark Ross cruise JR20140126 in March 2014.

Instrument setup

Related Data Activity activities are detailed in Appendix 1

Fixed Station Information

Fixed Station Information

iSTAR1 (trough_W)

Water depth = 605 m

Sampling history

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: iSTAR1

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: iSTAR1 (trough_W)

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.