Welcome to EBAS

EBAS is a database hosting observation data of atmospheric chemical composition and physical properties. EBAS hosts data submitted by data originators in support of a number of national and international programs ranging from monitoring activities to research projects. EBAS is developed and operated by the Norwegian Institute for Air Research (NILU). We hope the information found on the web-site is self explanatory, and we would particularly ask you to consider the text found in the data disclaimer and in the “info” pages associated to the filter criteria.

Data availability and data policy issues

All datasets in EBAS are associated to one or more “projects”, having individual rules for data disclosure (if a dataset is associated to several projects the one with the least restrictive data policy will actually limit the access). The project association is normally set by the data originator through the submission process, but can also be set by the data base management team at NILU. An automated access control unit is also in preparation.

- Public data

Most of the data stored in EBAS are originating from programs encouraging an unlimited and open data policy for non-commercial use. For scientific purposes, access to these data is unlimited and provided without charge. By their use you accept that an offer of co-authorship will be made through personal contact with the data providers or owners whenever substantial use is made of their data. In all cases, an acknowledgement must be made to the data providers or owners and to the project name when these data are used within a publication. Public data are available without login.

- Data with restrictions

Access to restricted data requires the user to approve the associated data policy. The approval process which follows may in simple cases be an automatic procedure where the users by default is granted access (a log of signed data policy agreements is stored at NILU), or in more restricted cases will the request be handled by an authorized person on behalf of the formal deciding body of the respective project.

For more information about data policies associated to the projects with data stored in EBAS, please visit the “info” page which is available from the projects search filter. Here one can also find information whether the data stored in EBAS represents a primary database or if they are a secondary copy. It also informs if NILU has a mandate to conduct QAQC efforts related to the data.

General disclaimer

EBAS was mainly developed during 1995-2000, and has since 2006 been running on an external server. This allows direct queries through a web interface (first version launched in 2008). The functionality for external users is still limited and under development. We encourages users to make direct contact with the database management group ( at NILU to get support for export of larger amounts of data in specific formats, calculation of statistics etc. More functionality can be expected in the period to come as we get more experience with the stability of the system.

Suggestions for improvements

We are happy to receive any comments you may have related to user friendliness, bugs, errors in datasets or other. For matters related to layout, please inform which web browser you have used. All feedback should be addressed to You should also note that there is already a list of developments under work including:

  • Search filters not to be reset when going back after viewing datasets and plots
  • Grouping of components (e.g. group POPs, group VOCs, group Aerosol physical properties etc.)
  • Possibility to plot or download aggregates (monthly, annual means etc.)
  • Graphical plots for non-continuous data to be developed (wet deposition, grab samples etc.)
  • Some rendering issues on Firefox, Opera, Safari
  • Display of detailed metadata linked from datasets/measurements
  • Download option for metadata lists (station list, component list, flag list)
  • certain condition the search filter falls in an undefined state (showing 0 available datasets and empty option list for some criteria page reload is a temporary workaround)
  • Integration of NILU's atmospheric transport resources (operational FLEXTRA and FLEXPART products)