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Metadata Report for BODC Series Reference Number 548998

Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
Plessey 9400 CTD  CTD; water temperature sensor; salinity sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator -
Originating Organization Institute of Oceanographic Sciences Bidston Laboratory (now National Oceanography Centre, Liverpool)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -

Data Identifiers

Originator's Identifier CH5/78/013
BODC Series Reference 548998

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1978-03-30 06:46
End Time (yyyy-mm-dd hh:mm) 1978-03-30 06:48
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 51.44170 N ( 51° 26.5' N )
Longitude 7.84400 W ( 7° 50.6' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 5.0 m
Maximum Sensor or Sampling Depth 78.9 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
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 -


BODC CODERankUnitsTitle
DEPHPR011MetresDepth (spatial coordinate) relative to water surface in the water body by profiling pressure sensor and conversion to seawater depth using UNESCO algorithm
PSALPR011DimensionlessPractical salinity of the water body by conductivity cell and computation using UNESCO 1983 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

Salinity noise up to 0.01 PSU.

Negative pressures down to -3db occur.

The affected values have been flagged, but their presence casts doubt on the pressure calibration.

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

Plessey 9400 Conductivity, Temperature and Depth

The Plessey 9400 comprises a Plessey 6500 inductive conductivity sensor, a Plessey 4500 platinum resistance temperature sensor and a Plessey 4600 bonded strain pressure sensor.

RRS Challenger 5/78 CTD Data Documentation


Documentation for the CTD data collected on RRS Challenger Cruise 5/78 (22 March - 4 April) by the Institute of Oceanographic Sciences, Bidston (now POL).

Port of Departure Barry
Port of Return Barry
Area Celtic Sea


Some of the salinity data collected on this cruise are noisy (±0.01 psu)

Data Processing

The raw data were previously manually edited, resequenced and archived in files. 0ne file contained temperature, salinity and depth frequencies with time elapsed and the other contained decca positional infomation.

This data set was reprocessed in Febuary 2001.


The following constants (obtained from printouts of the data) were used to convert to real units and calibrate.

Temperature Constant 2127.5
Salinity Constant 5001.6
Depth Constant 9718.0

The downcasts had a temperature correction applied to lessen salinity spiking.

REALT = TC(2) + ((TC(3)-TC(1))/2.0) * TIC


TC(1-3) = Three successive readings of temperature (in °C)
TIC = Timing constant of the instrument = 0.35

Project Information

No Project Information held for the Series

Data Activity or Cruise Information


Cruise Name CH5/78
Departure Date 1978-03-22
Arrival Date 1978-04-04
Principal Scientist(s)David T Pugh (Institute of Oceanographic Sciences Bidston Laboratory)
Ship RRS Challenger

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