Availability of high frequency sea level data

To discover the availability of European sea level data, in the autumn of 1997, questionnaires were sent to European GLOSS contacts and national sea-level recording bodies in northern Europe. One questionnaire was sent to each country. The questionnaire asked for information on tide gauges which produce data in computer-transmittable form, and also how such information is currently disseminated by laboratories.

Responses to High Frequency Questionnaire

Replies to the questionnaire on the availability of high frequency sea level data were received from the following agencies:

Agencies replying to questionnaire on the availability of high frequency sea level data
Agency Country
Afdeling Waterwegen Kust Hydrografie Belgium
Center of Marine Research (Oceanological department) Lithuania
Danish Meteorological Institute(Observation department, Operations division) Denmark
Estonian Meteorological and Hydrological Institute Estonia
Finnish Institute of Marine Research Finland
Icelandic Hydrographic Service Iceland
Institute of meteorology and water management (maritime branch) Poland
Instituto Espanol de Oceanografia Spain
Instituto Portugues de Cartografia e Cadastro Portugal
National institute for coastal and marine management, Rijkswaterstaat Netherlands
Ordnance Survey Ireland
Proudman Oceanographic Laboratory United Kingdom
Service Hydrographique et Oceanographique de la Marine (SHOM) France
Statens Kartverk Norway
Swedish Meteorological and Hydrological Institute (SMHI) Sweden
Federal Maritime and Hydrographic Agency Germany

Of these agencies, the following have web pages listing what data is available:


Agencies from the following countries currently require those interested in finding out what data is available to contact the relevant institute. (N.B. Due to countries' involvement in EOSS, and EuroGOOS, this situation will change rapidly)
Actual data is available over the web from all 11 of the Netherlands North Sea gauges, with a delay of 10 minutes. Denmark makes (non-quality controlled) data available from the previous 24 hours, and also submits data from Nuuk and Torshavn confidentially to GLOSS. Non operational (i.e. fully quality controlled) data is made available by POL for the three GLOSS sites in the British Isles (Lerwick, Stornoway and Nelwyn). The German Federal Maritime and Hydrographic Agency (Bundesamt für Seeschiffahrt und Hydrografie) are planning to make data available from their gauges at Cuxhaven, Borkum and Helgoland from the start of 1998.
At present, the following institutions do not release high frequency sea level data for general use, for commercial reasons:

Of the remainder, Belgium, Estonia, Iceland and Lithuania cited computer/ technical reasons for not being able to make data available. The Ordnance Survey (Ireland) had not been approached to supply data, so were not aware of the need to make data available. The Instituto Espanol was in favour of making data available, but did not have time at present to implement a system. Lithuania is currently installing self recording instruments, and the Center for Marine Research is taking over observation work from the Department of the Hydrometeorological Observatory.
SHOM (France) expect to make data available in the second semester of 1998. This data will be password protected for authorised users. Belgium and Iceland were willing to have data copied across to a central server at regular intervals, while SMHI and SHOM were willing to make a subset of their data holdings available.

The following comments were received regarding making data available:
Denmark Data is supplied to GLOSS on the condition that it is not made public
Estonia It may be possible to allow data to either go on a password- protected server, or to make a subset of data freely available. No data exchange policy has yet been finalised in Estonia
Finland Data can be accessed by ftp, following agreement with FIMR. Password protecting data on the web is acceptable, but FIMR would like to discuss an agreement with each user separately. Daily means of sea level can be made freely available.
France The number of people who request data is currently less than 10 per year. The use of data should be restricted to bona fide scientists on research work. Scientists should commit to using the data in the strict field of their studies, perhaps signing a charter or contract
Iceland Data will probably be available in the near future on a web site
Ireland Password protecting the data on the web is acceptable, but is dependent on the resources required from the Ordnance Survey
Netherlands Currently discussing security and charging issues, so the current policy may change in future. The Rijkswaterstaat are in favour of putting as much information as possible on the web
Norway All 23 gauges supply data in computer transmittable form. Planning to ease access to data, possibly by putting it onto ftp or WWW. Joining EOSS and GOOS means that the policy will be decided soon.
Poland The sea level data (6 readings from each mareogram per day) from all stations are collected in the database in computer-transmittable form. For special reasons, data can be supplied with 24 or more readings per day.
Spain Data can be made available within 1 day. More information is available on http://www.ieo.es. IEO is a National Oceanographic Data Centre (NODC) and exchanges data with other data centres, but a data policy is needed for dealings with private companies. The data policy needs to be agreed with the other three Spanish sea level agencies. Monthly means and graphs of sea level will be available on the web very soon.
Sweden SMHI will exchange data under GOOS/ EuroGOOS/BalticGOOS and SEANET. Data policy is as documented under WMO Resolution 40, and under ECOMET rules for commercial use. Scientific use is free, subject to a few conditions. Some stations will be available on ftp, in delayed mode.
United Kingdom Data may be made available if password protected

Conclusions

Data is currently available, or can be made available, in computer transmittableform from all countries in Northern Europe. Among countries with well established national tide gauge networks, most do not release data openly on theweb because of its perceived commercial value. From comments and plans, it appears that there is a general consensus agreeing to make data accessible to bona fide scientists engaged on research projects, and also the the WWW is the best medium for this data transfer. Agencies currently hold back from making data generally available in this way because:

As a result of discussions at the EOSS management meeting in Copenhagen, on the 16-17 December 1997, it was agreed that in order to protect agencies' commercial interests, data should be made available on the WWW, but in a password protected form. Frits Brouwer commented that the main challenges for this work package would be to agree quality control and formatting standards, in addition to making data available.
Further discussion suggested that hourly sea level data should be made available with the minimum of quality control (following guidelines worked out for WOCE sea level data). This work package should also define what additional data is required from tide gauge sites. A draft document describing proposed quality control on data, and defining what parameters are required will be presented for discussion at the next EOSS management meeting, to take place in Frankfurt, 15-16 June. Click here to go back

High Frequency Questionnaire

Survey of Possibility of Access to 'Higher Frequency' European Sea Level Data

  1. Country:
  2. Agency:
  3. Contact name, address, tel, fax, email:
  4. Gauges for which 'higher frequency' sea level data are available in computer transmittable form:
  5. How soon after recording can data be made available to interested users?
  6. Is sea level data holdings information available for the above gauges from your agency via ftp/web in some way?
  7. If yes, what is the ftp/web address?
  8. If no, how do interested users know what data are available?
  9. Are data (perhaps only the most recent, and computerised, subsets of historical data sets) themselves available via ftp/web in some way?
  10. If yes, what is the ftp/web address?
  11. If no, are the reasons computer-technical, or because data have restricted availability for commercial or other reasons?
  12. If no, and reasons are computer-technical, would it be acceptable to you for your data to be copied regular to a server at another agency which can make the data available via ftp/web?
  13. If no, and reasons are commercial or other, would it be acceptable if, for example, data were made available on ftp/web but were password-protected, enabling initial enquiries to establish if requirements were for scientific research (and data therefore free of charge) or commercial (and data therefore subject to charging).
  14. Or, again, if no, and reasons are commercial or other, would it be acceptable if some fraction of your data holdings was made freely available in some way, with the remainder restricted?
  15. Please provide any other comments you have on this topic.

Click here to see a map of tide gauges in Northern Europe

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