As an important milestone on the way to the second Tropospheric Ozone Assessment Report (TOAR), a new TOAR data infrastructure has been developed with a focus on FAIR data ( First data has been uploaded to the TOAR-II database and more data will continuously be added. The REST API provides rich functionality for searching and accessing metadata and data, which are always delivered together. Read access is open to everyone under CC BY 4.0. The database and its metadata is well documented as are the related services (go to for links to the services and the documentation). The TOAR data infrastructure will be assessed with respect to its FAIRness and sustainability through the Core Trust Seal (CTS, The CTS application was submitted on September 29, 2021.