Metadata Report for BODC Series Reference Number 36918


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) -
 

Data Identifiers

Originator's Identifier G4HP0/SMDFH0
BODC Series Reference 36918
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1981-12-15 16:00
End Time (yyyy-mm-dd hh:mm) 1982-03-10 00:00
Nominal Cycle Interval 3600.0 seconds
 

Spatial Co-ordinates

Latitude 9.98540 N ( 9° 59.1' N )
Longitude 50.51840 W ( 50° 31.1' W )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 4850.0 m
Maximum Sensor Depth 4850.0 m
Minimum Sensor Height 0.0 m
Maximum Sensor Height 0.0 m
Sea Floor Depth 4850.0 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)
PPSSRL01 1 Decibars RelBotPress Pressure (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 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.

Data Processing Notes

Clock gained 1 minute 33 seconds over 85 days 21 hours 58 minutes 27 seconds; the original cycle interval and time values have been corrected.

Instrument Characteristics

Station G4(H)

Teleost Sensor 286/4 (BODC Series Ref. 36918)
Nominal sampling interval 900secs
Integration period 900secs
Actual sampling interval 14.999812mins

IOS Data Processing of Off-Shore Pressure Recorder Data

Data processing consists of two stages:-

  1. Pressures have been sample rate reduced from the basic time step of the recorder to produce the hourly values and have been interpolated by a cubic spline to generate the value on cardinal hours.

  2. Instrumental drift has been removed and the drift free series is produced with an artificial mean value, usually of 100mbar.


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