Metadata Report for BODC Series Reference Number 846264

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

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

DATARING Datalogger Tide Gauge

The DATARING logger takes signals from Digiquartz pressure transducers and pressure operated gauges which are connected to the tidal pressure by a bubbler system. Float operated gauges can also supply a sea level signal to the datalogger. A number of sites also collect wind speed and direction data. The signals are processed to take account of water density, datum offset and calibration factors.

The data are averaged over a 15 minute period, with the centre points being o'clock, quarter past, half past, and quarter to. These readings are stored in internal memory and approximately 14 days can elapse before data are likely to be overwritten. The data can be accessed by POL and the Storm Tide Forecasting Service either locally or remotely over the telephone line. The data are retrieved on a weekly basis and appended onto the existing database, giving a continous record for each site.

Dataring direct pressure transducer

A submersible differential transducer contained in a watertight housing. The reference port is vented to the atmosphere via the power supply and signal cable, while the measuring port of the transducer is connected to a copper outlet nozzle, on the top of the transducer housing. The nozzle, measuring port and connecting tube are filled with oil, so the pressure is transmitted to the crystal element via the oil, thus keeping the instruments components free from the effects of saltwater.

Project Information

UK Tide Gauge Network

The national network of 'Class A' sea level gauges are deployed at 47 sites around the coast of the U.K.

The network was established after the serious flooding of the Thames estuary in 1953, which resulted from a violent storm in the North Sea.

The network sets out to obtain high quality tidal information through telemetry and provide warning of any possible flooding of coastal locations around the British Isles.

Data Activity or Cruise Information

No Data Activity or Cruise Information held for the Series

Fixed Station Information

Fixed Station Information

Avonmouth Site History

History Summary

Benchmark descriptions

ODN = Ordnance Datum Newlyn

Datum Information

Tide Gauge Zero (TGZ) = Admiralty Chart Datum (ACD)

Corrected Timing Errors

The table below lists the notified time errors for which corrections have been made (if the time error is positive the clock was fast, and if negative the clock was slow):

1973: 21 missing errors

1974: 39 missing errors

1975: 24 missing errors

1979: 1 missing error

1980: 1 missing error

1982: 3 missing errors

Corrected Datum Errors

1973: 1 missing error

1974: 1 missing error

1975: 5 missing errors

Benchmark Relationships

TGZ = 6.50 m below Ordnance Datum Newlyn (ODN)
TGZ = 15.711 m below TGBM

Note: Please also see document 83034

Quality Assessment

All data have been compared with the current Harmonic Constants library, and residuals checked. Records have been visually inspected for spikes, datum shifts and timing errors.

In March 1993, the bubbler gauges (ASLVBG0*) were replaced by pressure transducers (ASLVTD0*).

From the beginning of January 2004, channel two (ASLVTD02) became the primary channel and channel one (ASLVTD01) became the backup channel.

The completeness index is given for the primary channel only.

Avonmouth Datum Information 1986-

Benchmark Relationships

• TGZ = Chart Datum = 6.50m below ODN
• TGZ = Chart Datum = 15.711m below TGBM
• TGZ = Chart Datum = 15.98m below Aux 1
• TGZ = Chart Datum = 15.956m below Aux 2

Glossary

• TGZ = Tide Gauge Zero
• TGBM = Tide Gauge Benchmark
• AUX = Auxiliary Benchmark
• ODN = Ordnance Datum Newlyn
• CD = Chart Datum

Related Fixed Station activities are detailed in Appendix 1

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: Avonmouth

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

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