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Metadata Report for BODC Series Reference Number 491541


Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
NameCategories
Sea-Bird SBE 19 SEACAT CTD  CTD; water temperature sensor; salinity sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator -
Originating Organization University of Wales, Bangor School of Ocean Sciences (now Bangor University School of Ocean Sciences)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -
 

Data Identifiers

Originator's Identifier PM6/95/D8
BODC Series Reference 491541
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1995-08-16 15:49
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars
 

Spatial Co-ordinates

Latitude 54.00000 N ( 54° 0.0' N )
Longitude 4.83300 W ( 4° 50.0' W )
Positional Uncertainty Unspecified
Minimum Sensor or Sampling Depth 2.0 m
Maximum Sensor or Sampling Depth 49.5 m
Minimum Sensor or Sampling Height 8.5 m
Maximum Sensor or Sampling Height 56.0 m
Sea Floor Depth 58.0 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
ACYCAA011DimensionlessSequence number
PRESPR011DecibarsPressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
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

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 19 and SBE 19plus SEACAT Profiler CTDs

The SBE 19 SEACAT Profiler is a self-contained, battery powered, pumped CTD system designed to measure conductivity, temperature, and pressure in marine or fresh water environments to depths of 10,500 meters. It was replaced by the SBE 19plus model in 2001. An updated version of this instrument is the SBE 19plus V2, which incorporates an electronics upgrade and additional features, with six differentially amplified A/D input channels, one RS-232 data input channel, and 64 MB FLASH memory.

The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by titanium housing for depths up to 7000 m. It is typically used for CTD profiling although a conversion kit is available for mooring deployments. The CTD can also be attached to an SBE 36 CTD Deck Unit and Power/Data Interface Module (PDIM) for real-time operation on single-core armored cable up to 10,000 m.

Specifications

Parameter SBE 19 SBE 19plus
Temperature

Range: -5 to +35 °C

Accuracy: 0.01 °C

Resolution: 0.001 °C

Calibration: +1 to +32 °C*

Range: -5 to +35 °C

Accuracy: 0.005 °C

Resolution: 0.0001 °C

Calibration: +1 to +32 °C*

Conductivity

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

Accuracy: 0.001 S m-1

Resolution: 0.0001 S m-1

Calibration: 0 to 7 S m-1. Physical calibration over the range 1.4 - 6 S m-1*

Range: 0 to 9 Sm-1

Accuracy: 0.0005

Resolution: 0.00005 (most oceanic waters, resolves 0.4 ppm in salinity); 0.00007 (high salinity waters, resolves 0.4 ppm in salinity); 0.00001 (fresh waters, resolves 0.1 ppm in salinity)

Calibration: 0 to 9 S m-1. Physical calibration over the range 1.4 - 6 S m-1*

Strain gauge pressure sensor

Range: 0 to100, 150, 300, 500, 1000, 1500, 3000, 5000, 10000 or 15000 psia

Accuracy: 0.25% of full scale range (100 - 1500 psia); 0.15% of full scale range (3000 - 15000 psia)

Resolution: 0.015% of full scale

Calibration: 0 to full scale in 20% steps

Range: 0 to 20, 100, 350, 1000, 2000, 3500 or 7000 m

Accuracy: 0.1% of full scale range

Resolution: 0.002% of full scale range

Calibration: ambient pressure to full scale range in 5 steps

*Measurements outside this range may be at slightly reduced accuracy due to extrapolation errors.

Options and accessories

Additional sensors can be attached to the CTD, including:

  • high accuracy Paroscientific Digiquartz pressure sensor (depth range 0 to 20, 60, 130, 200, 270, 680, 1400, 2000, 4200, 7000 or 10500 m; accuracy 0.02% of full scale; resolution 0.0025% of full scale)
  • 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 standard SBE 5M pump may be replaced by an SBE 5P (plastic housing) or 5T (titanium housing) pump for use with dissolved oxygen and/or other pumped sensors. Further details can be found in the manufacturer's SBE 19plus V2 instrument specification or theSBE 19 andSBE 19 plus user guides.

RV Prince Madog Cruise PM6/95 CTD Data Documentation

Introduction

Documentation for the CTD data from a series of cruises in the western Irish Sea carried out by University of Wales, Bangor during 1995 on the RV Prince Madog under the direction of Dr A.E. Hill. The work was supported by NERC grant GR3/9601, "Seasonal Gyres in Shelf Seas".

The data is already calibrated. Coefficients and method are given below. Density has been derived using the formulation recommended in Unesco Tech. reports 36,38,40 (1981).

Instrumentation

The instrument used was a Sea-Bird SBE 19 profiling CTD. In all cases, observed parameters were pressure, temperature and conductivity.

Sampling Protocol

The typical instrument descent rate was 1 m/s. Data were logged on an IBM compatible PC.

Data from the SBE 19 was collected using Seasoft Version 4.211

Data Processing

Data from the SBE 19 were processed with Seasoft Version 4.211

In all cases, data were checked for rogue values and averaged into 1m depth bins. Calibration coefficients were subsequently applied using an in-house program which created the files sent to BODC.

Calibration

Temperature was calibrated using standard reversing thermometers (0.001 °C accuracy) and salinity samples from a rosette. Salinity samples were measured with Autosal Model 8400A. Samples were collected from well mixed regions of the water column to ensure good calibration.

Temperature

Temperature calibration was calculated as a difference:

Temperature = CTD temperature + dT (°C)

Salinity

Salinity calibration was calculated as a ratio:

Salinity = CTD salinity / Sr Cruise PM6_95

Number of samples 36
Mean dT 0.016
Standard deviation dT 0.004
Mean Sr 1.002
Standard deviation Sr 0.0006

Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Cruise

Cruise Name PM6/95
Departure Date 1995-08-14
Arrival Date 1995-08-17
Principal Scientist(s)
Ship Prince Madog

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