Metadata Report for BODC Series Reference Number 33982

Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
Teleost Pressure Recorder  sea level recorders; water temperature sensor
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
Project(s) IOS Celtic Sea Experiment 1978

Data Identifiers

Originator's Identifier 786/978/089
BODC Series Reference 33982

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1978-03-30 20:22
End Time (yyyy-mm-dd hh:mm) 1978-05-15 00:21
Nominal Cycle Interval 900.0 seconds

Spatial Co-ordinates

Latitude 50.54990 N ( 50° 33.0' N )
Longitude 7.53330 W ( 7° 32.0' W )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 108.0 m
Maximum Sensor Depth 108.0 m
Minimum Sensor Height 0.0 m
Maximum Sensor Height 0.0 m
Sea Floor Depth 108.0 m
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor 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


BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
PRSTPS01 1 Decibars TotPressSeaFL Pressure (measured variable) exerted by the water body plus atmosphere by fixed in-situ pressure sensor

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 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

Teleost Pressure Recorder

This instrument was developed at I.O.S. Bidston. Each recorder consists of a Bell and Howell strain gauge or a Digiquartz pressure transducer. The strain gauge sensor uses a Bell and Howell type 4-306 transducer and operates as a phase shift oscillator whose frequency is controlled by the ratio of output to input voltage of the transducer Wheatstone bridge network. The quartz crystal pressure sensor consists of a convoluted bellows linked to a 40kHz quartz crystal resonator coupled by piezoelectric action to an electronic resonator.

The pressure and temperature recorder consists of an Aanderaa current meter type logger modified to accept input from a pressure sensor containing a Bell and Howell strain gauge or a Digiquartz pressure transducer and a platinum resistance thermometer.

The pressure and temperature transducers are mounted in the same heat sink for compatible data. The pressure sensors are mounted in a protective frame of dimensions 1.75m by 1.14m by 0.66m, attached to a ballast plate or frame. Teleost recorders are deployed as pop-up moorings and released from their ballast frames by firing a pyrotechnic release by acoustic command.

IOS Calibration and Data Processing of Off-Shore Tide Gauge Data

Calibration of pressure/frequency sensors and thermistors are carried out using the facilities and staff at I.O.S. Bidston with the exception of pre 1975 pressure/frequency sensors, which were calibrated in the pressure chamber at I.O.S. Wormley.

The data are copied from the logger magnetic tape to 9 track magnetic tape and disk. The data are either listed or plotted as an initial check. A program is then used to check the data from the temperature sensor channels, calculate and plot the temperature values and store them (if temperature sensor channels are available).

A second program performs a similar function for the pressure sensor channel, using the pressure frequency coefficient to convert each pressure frequency to the frequency at the reference temperature and calculating the pressures using the pressure frequency calibration. The data values, generally at 15 minute intervals, but occasionally at 10 minute intervals, of pressure are then plotted and stored. If waterhead is required, it may be computed by subtracting atmospheric pressure and applying the hydrostatic relation:-

H = P / ( d * g )
H = waterhead (cm)
P = pressure (0.01 mb)
d = density (kg/m3)
g = gravitational acceleration (m/s2)

Station F (Celtic Sea) Data Processing Notes

Clock gained 57 seconds over 70 days, 16.75 hours; the cycle interval and time values have been corrected.

Instrument characteristics and calibration factors

Teleost Pressure Recorder, sensor DIG, serial number 281
Original sampling interval 15 minutes
Integration period 900 s
Temperature coefficient -0.242 Hz/°C
Pressure sensitivity at 9.03 °C 0.04271 Hz/mb

To convert pressure to elevation the following values should be used:

Density (from CTD casts) 1027.1 kg/m 3
Gravitational acceleration constant 9.811 m/s 2

Two current meters were also deployed on this rig.

Project Information

IOS Celtic Sea Experiment 1978

This experiment was conducted by I.O.S. Bidston in the Celtic Sea and South West Approaches to the U.K. during the period March to May 1978.

Currents and sea bed pressures were measured at each of eight stations in the Celtic Sea and one station in 4000m of water at the shelf edge. Aanderaa thermistor chains were deployed at four of the stations and profiles of sea water conductivity and temperature with depth were taken during the cruises and sea surface temperatures and conductivity were continuously monitored. Coastal tide gauges measured sea surface elevation at six sites.

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