TOAR Data Infrastructure

Mission Statement

The Tropospheric Ozone Assessment Report (TOAR) data centre is the central hub for data access in support of research assessing the impacts of ozone air pollution on human health, vegetation, and climate. Besides maintaining a data portal with links to ozone data sets from research organisations all over the world, we operate a database of harmonised surface ozone measurements and related data. This is one of the largest collections of quality controlled air pollution measurements in the world. All data in the database are easily accessible through open, freely available and well documented web services. The TOAR data centre team is committed to the FAIR principles and aims to achieve the highest standards with respect to data curation, archival, and re-use.

Terms of Use


TOAR V2 supports the second phase of the TOAR activity



Current content of the database: status and plans, numbers

User Guides

Technical Guides

General Guides


TOAR V1 supported the first phase of the TOAR activity


Services for TOAR-V1 have been closed in February 2024.


  • JOIN Documentation (pdf) - FAQ
  • Schultz, M. et al., 2017; Tropospheric Ozone Assessment Report: Database and Metrics Data of Global Surface Ozone Observations; Elementa Sci. Anthrop.;

TOAR is an activity of the International Global Atmospheric Chemistry organisation programme. The FAIR principles for open research data are described at