Submitting data to BODC

Sea level data submission

The following provides details for assembling a sea level data set for submission to BODC. Instructions for other data sets and general details for transferring the data to BODC are available from the main data submission page.

Data standard

Raw and quality controlled water level data should, whenever possible, be stored at the original sampling frequency. For water level data, hourly observations are recommended as a minimum.

All parameters must be clearly specified and described. If parameter codes are to be used, then these must be fully documented or the source data dictionary must be specified. Parameter units must be clearly stated. Parameter scales must be noted where applicable. If computed values are included, the equations used in the computations should be stated.

All relevant calibrations should be applied to the data including laboratory and field calibrations. Instrument calibration data should be included in the data file. The data should be fully checked for quality and flagged for erroneous values such as spikes, gaps, etc. An explicit statement should be made of the checks and edits applied to the data. If any data values have been removed, the times of the removed values should be noted.

In particular

Format description

Data can be supplied in a fully documented ASCII format or netCDF. Individual fields, units, etc. should be clearly defined and time zone stated.

Sample Metadata

Sufficient documentation should accompany each data series so as to ensure that the data are adequately qualified and may therefore be used with confidence by a secondary user. Such documentation should be stored alongside the data, and where applicable, should cover

Collection Details

Pertinent information to be included in the data transfer to BODC

Instrument details

Site details

Data sampling/processing

Report on data quality

Report any quality control procedures applied to the data set (manual or automatic) or any additional information of use to secondary users which may have affected the data or have a bearing on their subsequent use (e.g. effects of sea state, fouling, etc.).

Annex 1

Recommended documentation relevant to common instrument types

  1. Acoustic gauge. Documentation should include whether the sensor operates within a sounding tube or in the open air, details of instrument calibration, details of temperature sensors, size of tube, ancillary sensors, details of datum control.
  2. Radar or optical (laser) gauge. As for acoustic gauge except for the need of temperature sensor(s).
  3. Step gauge. Documentation should include electrode diameter, electrode mutual spacing, sampling frequency and time averaging interval.
  4. Pressure transducer. Documentation should include a statement on whether the data have been converted to elevation, and the appropriate values of water density and acceleration due to gravity used/to be used in the conversion. Details of calibration and sensor drift, and whether drift has been removed. Information relating to atmospheric pressure, whether values are total pressure — or if atmospheric pressure has been removed.
  5. Bubbler gauge. Documentation should include tube length, tube diameter, orifice diameter, density value used to convert to elevation, acceleration due to gravity and the formula used to compensate for tube length.
  6. Conventional stilling well. Documentation should include well diameter, orifice diameter, orifice depth below mean water level and orifice height above seabed.
  7. Bottom-mounted pressure recorder. Documentation should include a statement on whether the data have been converted to elevation, and the appropriate values of water density and acceleration due to gravity used/to be used in the conversion. Details of instrumental drift, and whether it has been removed.


Related BODC pages

UK Tide Gauge Network     Global Sea Level Observing System (GLOSS)
World Ocean Circulation Experiment (WOCE) sea level     Climate Variability and Predictability (CLIVAR) — Sea level data submission

Related external pages

Permanent Service for Mean Sea Level (PSMSL)