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 v2.2 and contains all functionality described in the v2.2 Reference Guide. Additional functionality can be added in consultation with TNO.


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. The next user workshop will be held at TNO Utrecht at the start of 2024.

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

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 can be requested using the application form on the MACC website.

Community Portal

The use of the LOTOS-EUROS open-source version is regulated by means of a community site.

Logging on to the community site gives access to the source code, a test bed with input data and verification output, a wiki and a user forum. Alerts can be sent when model updates are available.

To gain access to the community site you can request access using the online form.