Metadata Report for BODC Series Reference Number 34205


Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
NameCategories
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 North Sea Experiment 1981
 

Data Identifiers

Originator's Identifier 817/981/129
BODC Series Reference 34205
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1981-05-09 08:07
End Time (yyyy-mm-dd hh:mm) 1981-06-15 15:22
Nominal Cycle Interval 900.0 seconds
 

Spatial Co-ordinates

Latitude 55.58330 N ( 55° 35.0' N )
Longitude 0.75990 E ( 0° 45.6' E )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 75.0 m
Maximum Sensor Depth 75.0 m
Minimum Sensor Height 0.0 m
Maximum Sensor Height 0.0 m
Sea Floor Depth 75.0 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
 

Parameters

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 J (North Sea) Data Processing Notes

Clock lost 10 seconds over 53 days, 23.75 hours; the cycle interval and time values have been corrected.

Instrument Characteristics and Calibration Factors

Teleost Pressure Recorder, sensor DIG, serial number 288

Original sampling interval 15 minutes
Integration period 900s
Temperature coefficient 0.0mb/°C
Pressure sensitivity at 7.931°C 0.0598Hz/mb

Project Information

IOS North Sea Experiment 1981

An experiment was carried out by I.O.S. Bidston in the North Sea during May and June 1981. The scientific objectives were:

  1. To investigate the slope of the mean sea level surface between Leith and Immingham.
  2. To study the tidal energy budget in a shallow coastal region.
  3. To measure currents around a sandbank to test theories of spring neap changes in the mean currents.

24 rigs containing recording current meters, thermistor chains or pressure recorders were deployed for 40 days at 15 stations. Data from nearby coastal tide gauges were also used. The density field was measured during both the deployment and recovery legs by continuous monitoring of sea surface temperature and conductivity and by recording CTD profiles.


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