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Metadata Report for BODC Series Reference Number 1196263

Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
Neil Brown MK3 CTD  CTD; water temperature sensor; salinity sensor; dissolved gas sensors
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Carol Pudsey
Originating Organization British Antarctic Survey
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Marine Geophysics Scotia, Bellingshausen

Data Identifiers

Originator's Identifier CTD046_REFORMATTED
BODC Series Reference 1196263

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1990-03-12 14:45
End Time (yyyy-mm-dd hh:mm) 1990-03-12 17:30
Nominal Cycle Interval 1.0 decibars

Spatial Co-ordinates

Latitude 60.18833 S ( 60° 11.3' S )
Longitude 38.14000 W ( 38° 8.4' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 1.0 m
Maximum Sensor or Sampling Depth 2949.7 m
Minimum Sensor or Sampling Height 19.3 m
Maximum Sensor or Sampling Height 2968.0 m
Sea Floor Depth 2969.0 m
Sea Floor Depth Source CRREP
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Unspecified -


BODC CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
POTMCV011Degrees CelsiusPotential temperature of the water body by computation using UNESCO 1983 algorithm
PRESPR011DecibarsPressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
PSALST011DimensionlessPractical salinity of the water body by CTD and computation using UNESCO 1983 algorithm
SIGTPR011Kilograms per cubic metreSigma-theta of the water body by CTD and computation from salinity and potential temperature using UNESCO algorithm
TEMPST011Degrees CelsiusTemperature of the water body by CTD or STD

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:

"Contains public sector information licensed under the Open Government Licence v1.0."

Narrative Documents

Neil Brown MK3 CTD

The Neil Brown MK3 conductivity-temperature-depth (CTD) profiler consists of an integral unit containing pressure, temperature and conductivity sensors with an optional dissolved oxygen sensor in a pressure-hardened casing. The most widely used variant in the 1980s and 1990s was the MK3B. An upgrade to this, the MK3C, was developed to meet the requirements of the WOCE project.

The MK3C includes a low hysteresis, titanium strain gauge pressure transducer. The transducer temperature is measured separately, allowing correction for the effects of temperature on pressure measurements. The MK3C conductivity cell features a free flow, internal field design that eliminates ducted pumping and is not affected by external metallic objects such as guard cages and external sensors.

Additional optional sensors include pH and a pressure-temperature fluorometer. The instrument is no longer in production, but is supported (repair and calibration) by General Oceanics.


These specification apply to the MK3C version.

Pressure Temperature Conductivity

6500 m

3200 m (optional)

-3 to 32°C 1 to 6.5 S cm-1

0.0015% FS

0.03% FS < 1 msec


0.003°C < 30 msec

0.0001 S cm-1

0.0003 S cm-1 < 30 msec

Further details can be found in the specification sheet.

RRS John Biscoe cruise JB10 Leg 3 BODC data processing

The files were processed and calibrated at the British Antarctic Survey and were sent to BODC in excel format. The following parameters were sent: pres, sal, temp, sigma-t, ptemp,sigma-th, press/10, sal/10, ptemp/10, but not all were transferred as it was not clear how the originator obtained them.

The data were converted to BODC internal format (a netCDF subset) using BODC established procedures. Two parameters were derived by BODC. The following table shows how the variables within the originator's files were mapped to appropriate BODC parameter codes:

Originator's Parameter Name Units Description BODC Parameter Code Units Comments
press - Pressure (spatial co-ordinate) exerted by the water body by profiling pressure sensor and corrected to read zero at sea level PRESPR01 dbar -
temp - Temperature of the water body by CTD or STD TEMPST01 °C -
sal - Practical salinity of the water body by CTD and computation using UNESCO 1983 algorithm PSALST01 - -
- - Potential temperature of the water body by computation using UNESCO 1983 algorithm POTMCV01 °C Derived by BODC
- - Sigma-T of the water body by computation from salinity and temperature using UNESCO algorithm SIGTPR01 Kg m-3 Derived by BODC

Reformatted CTD data were visualised using the in-house graphical editor EDSERPLO. Quality control flags were applied to data as necessary.

RRS John Biscoe cruise JB10 Leg 3 CTD originator's data processing

Sampling Strategy

A total of 19 CTD profiles were performed during the cruise. The bottles were fired at different depths throughout the water column. Water samples were also collected for studies on phytoplankton, suspended particulate matter, oxygen isotopes and salinity.

Instrument Descriptions

CTD Unit and Auxiliary Sensors

The CTD unit consisted of a Neil Brown MkIII attached to a carousel with 12 x 2.5 l bottles. The CTD sensors were pressure, conductivity and temperature.

Field Calibrations

Many water samples were taken for salinity meansurements but unfortunately the on-board Autosal proved to be unusable in anything other than flat,calm conditions. Therefore the salinity calibrations were done back at Cambridge. Calibrations were performed laboriously using the BAS Microcomputer.

Project Information

Marine Geophysics- Scotia and Bellingshausen


Marine geoscience in the Scotia and Bellingshausen Seas was one of the main research interests for British Antarctic Survey (BAS). The investigations were carried out by a group of scientists based at the University of Birmingham, which was absorbed by BAS in the mid- 1980's.

The different survey methods included, amongt others, multichannel and single channel seismic reflection, deeptow boomers, GLORIA (Geological Long Range Inclined Asdic) side-scan sonar and HAWAII-MR1 (HIGP Acoustic Wide_Angle Imaging Instrument) swath bathymetry and side-scan sonar.

This project was funded by BAS and most of the surveys were also carried out by this institution.

Scientific Objectives

This project was carried out in order to gain a better understanding of the Southern Ocean's:

  • Tectonic history
  • Active tectonic processes
  • Paleoceanography
  • Stratigraphy
  • Ice dynamics during glacial intervals

Data Availability

Data sets collected during this project are available to the academic community.

Data Activity or Cruise Information


Cruise Name JB10 Leg 3
Departure Date 1990-02-28
Arrival Date 1990-03-23
Principal Scientist(s)Carol J Pudsey (British Antarctic Survey)
Ship RRS John Biscoe

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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