Open Source Version

It is our belief that a model is improved when more people use and develop it. In line with this vision, LOTOS-EUROS has been made available without charge in an open-source version. This open-source version is based on LOTOS-EUROS v2.3 and contains all functionality described in the v2.3 Reference Guide. Additional functionality can be added in consultation with TNO.

For more information: contact with 'Open Source' in the subject.


An international user workshop on the open source version of LOTOS-EURO is held every year. Experienced users, new users and potential users share their results and interests in an informal setting. Information on the most recent last workshop (held Jan 25/26, 2024 at TNO Utrecht) can be found in the information leaflet. The date for the 2025 workshop will be revealed in due course.

Computing Environment

Please note that LOTOS-EUROS is written in Fortran and is designed for Unix/Linux platforms, with Python scripts to handle compilation. Input and output data take up considerable space.

Input data

The open-source version does not include meteorological fields to drive the model, but does provide static input (emissions and time profiles, land use and climatological boundary conditions).

The latest set of emission data for Europe developed by TNO for use in the EU MACC (Monitoring Atmospheric Composition and Climate) project can be made available in various forms on request. These data were available on the MACC website, but the site appears to be taken offline. Apologies for this, we'll provide a new link as soon as possible.

Code availability

The use of the LOTOS-EUROS open-source version is regulated via registration. To gain access to the code and example data you can request access using the online form.

You will receive the login details for a GitLab account, where you can download the code, and an FTP account, where you can download input data (emissions, time profiles, land use, boundary conditions).