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Metadata Report for BODC Series Reference Number 41503


Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
NameCategories
Institute of Oceanographic Sciences MkIV bottom pressure recorder  sea level recorders
Instrument Mounting fixed benthic node
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 T3DP4/PDFH1
BODC Series Reference 41503
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1978-09-11 21:58
End Time (yyyy-mm-dd hh:mm) 1978-10-06 16:58
Nominal Cycle Interval 3600.0 seconds
 

Spatial Co-ordinates

Latitude 3.13130 N ( 3° 7.9' N )
Longitude 25.05910 W ( 25° 3.5' W )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor or Sampling Depth 4200.0 m
Maximum Sensor or Sampling Depth 4200.0 m
Minimum Sensor or Sampling Height 0.0 m
Maximum Sensor or Sampling Height 0.0 m
Sea Floor Depth 4200.0 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of 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
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
PPSSRL011DecibarsPressure (measured variable) exerted by the water body by fixed in-situ pressure sensor and corrected using co-located air pressure data expressed to unspecified datum by subtraction of a constant

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

IOS Mk IV Pressure Recorder

This instrument was developed at I.O.S. Bidston and is a deep water pressure recorder (i.e. used at depths between 300m and 5000m). Each recorder consists of one or two Bell and Howell strain gauges and/or a Digiquartz pressure sensor and a temperature sensor.

The sensors are interfaced into a Seadata cassette recording system. Sampling is usually every 3.75 minutes with the integration period equal to the sampling interval, but may be set to other sampling intervals. For example with a 3 second sampling interval and integration period the instrument may be used as a wave recorder.

The recorder is housed in a tubular aluminium frame 1.3m in diameter by 1.4m in height attached to a disposable steel ballast weight. The data logger together with the associated battery supply is lowered into a central 15cm (internal diameter) aluminium tube. Sensors are mounted externally with Marsh Marine connectors. The assembly free falls to the sea floor. An acoustic release system is used to separate the ballast weight and buoyancy is provided by Corning glass spheres attached to the aluminium frame.

Data Processing Notes

Clock lost 11 seconds over 27 days 2 hours 15 minutes 11 seconds; the cycle interval and time values have been corrected.

Instrument Characteristics

Station T3

OSTG Mark IV  
Sensors SG 2/D5 (BODC Series Ref. 41496,41503)
SG 1/D6 (BODC Series Ref. 41515)
SG 2/D6 (BODC Series Ref. 41527)
Nominal sampling interval 225 seconds
Integration period 225 seconds

IOS Data Processing of Off-Shore Pressure Recorder Data

Data processing comprises 2 stages:-

  1. Instrumental drift and depth are removed, thus the drift free series is produced with an artificial mean of zero.

  2. Generally the pressure values have been obtained by integration and averaging over the sampling interval, followed by logging; hence the time value assigned to a data cycle has been chosen as the mid-point between the start and end time of each interval. Some pressure records have been sample rate reduced from the basic time step of the recorder to produce either hourly or 15 minute values, incorporating any timing corrections due to clock error.


Project Information


No Project Information held for the Series

Data Activity or Cruise Information


No Data Activity or Cruise Information held for the Series


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