1. Introduction

The TOAR Database Infrastructure is a hub for tropospheric ozone data rather than a classical data archive for such data. Times series data from established networks of stations as well as data from individual measuring stations is collected, curated, augmented with quality indicators, and stored permanently in the TOAR database. In case networks are later changing their data due to their curation process, it will again be collected, run through the ingestion process and changed in the TOAR database. Version numbers attached to the data and metadata as well as earlier published database dumps still reflect the previous status.

The individual measuring stations together with the managed and unmanaged networks of stations form the group of data producers. The TOAR management is done by the IGAC project activity TOAR (https://igacproject.org/index.php/activities/TOAR), specifically by the Steering Committee of TOAR Phase-II, and the designated community is the TOAR community, more general all researchers who analyse tropospheric ozone data with respect to the global-scale impact of ozone on climate, human health and crop/ecosystem productivity.