The tropospheric ozone assessment report (TOAR; http://www.igacproject.org/activities/TOAR) is published as a series of peer-reviewed publications in the journal Elementa - Science of the Anthropocene (see https://collections.elementascience.org/toar). TOAR has established the world's largest collection of surface ozone data and generated a set of data products which can be readily used by the community for impact assessments, model evaluation, etc. This resource provides a link to the repository of pre-compiled datasets on PANGAEA. The TOAR database is also accessible via the Jülich Open Web Interface (JOIN; https://join.fz-juelich.de).