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Metadata Report for BODC Series Reference Number 462770


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 25 Sealogger CTD  CTD; water temperature sensor; salinity sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Dr Bill Turrell
Originating Organization Scottish Office Agriculture Environment and Fisheries Department Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -
 

Data Identifiers

Originator's Identifier SC13/95/0259
BODC Series Reference 462770
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1995-09-22 21:24
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 60.47780 N ( 60° 28.7' N )
Longitude 2.51380 E ( 2° 30.8' E )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 1.98 m
Maximum Sensor or Sampling Depth 83.19 m
Minimum Sensor or Sampling Height 16.81 m
Maximum Sensor or Sampling Height 98.02 m
Sea Floor Depth 100.0 m
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 Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODERankUnitsTitle
CNDCST011Siemens per metreElectrical conductivity of the water body by CTD
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
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

Public domain 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.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."


Narrative Documents

Sea-Bird SBE 25 SEALOGGER CTD

The SBE 25 SEALOGGER is a research-quality CTD profiling system used for coastal, estuarine and, can also be a practical option, for deep-water work. It is easily configured in the field for a wide range of auxiliary sensors. The SEALOGGER is self-powered, requires no conductive cable, and is designed for use up to 6800 meters (10,000 psia). It uses the SBE3F temperature and SBE4 conductivity sensors as well as having an external strain gauge pressure sensor. It provides pump-controlled T-C ducted flow, samples at 8 Hz, records internally and provides simultaneous real-time data via its built-in RS-232 interface.

The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by aluminium housing for depths up to 6800 m.

Specifications

Parameter SBE 25
Temperature

Range: -5 to +35 °C

Accuracy: 0.002 °C

Resolution: 0.0003 °C

Conductivity

Range: 0 to 7 S m-1 (0 to 70 mmho cm-1)

Accuracy: 0.0003 S m-1

Resolution: 0.00004 S m-1

Strain gauge pressure sensor

Range: 0 to 20, 100, 350, 600, 1000, 2000, 3500, 7000 metres (expressed in metres of deployment depth capability)

Accuracy: 0.1% of full scale range

Resolution: 0.015% of full scale range

Options and accessories

Additional sensors can be attached to the CTD, including:

  • Dissolved Oxygen (SBE 43 DO Sensor)
  • pH (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor)
  • fluorescence
  • radiance (PAR)
  • light transmission
  • optical backscatter (turbidity)

The SBE 5T titanium pump can be used in place of SBE 5P pump. Further details can be found in the manufacturer's SBE 25 instrument specification.

BODC Processing

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

Original parameter name Original Units Description BODC Parameter Code BODC Units Comments
Pressure dbar Pressure exerted by the water column PRESPR01 dbar -
Temperature degrees Celsius Temperature of the water column TEMPST01 degrees Celsius -
Conductivity Milli siemens per centimeter, Electrical conductivity of the water column CNDCST01 Siemens per metre Conversion by transfer
- - Practical salinity of the water column PSALST01 Dimensionless Calculated by BODC

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.

Originator's Data Processing

Sampling strategy

A total of 75 CTD cast were performed during this cruise. Of these casts, 39 were made in the standard Faroe-Shetland Channel. Due to bad weather it was not possible to sample along the JONSIS line but 36 CTD casts were made in the North Sea across the Viking Bank.

Data Processing

FRS applied the standard manufacturers' calibrations to all data, and produced ASCII files for submission to BODC.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name 1395S
Departure Date 1995-09-15
Arrival Date 1995-09-27
Principal Scientist(s)Bill Turrell (Scottish Office Agriculture Environment and Fisheries Department Aberdeen Marine Laboratory)
Ship FRV Scotia

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
Q value below limit of quantification