2000-2013 ozone trends across Europe

Tropospheric ozone (O3) has been recognized as an important factor within global change, that has the capacity of reducing carbon sink strength of forest ecosystems and thus represents a priority for the UNECE Convention on Long-range Transboundary Air Pollution. The ICP Forests Expert Panel on Ambient Air Quality has coordinated the monitoring of ozone concentration and effects (i.e. foliar injury on native vegetation) since 2000 on an annual basis on intensive long-term forest monitoring sites across Europe (Level II). Methodologies, including quality assurance such as data harmonization, completeness and plausibility tests have been applied according to the ICP Forests Manual, parts X and XV (Schaub et al. 2010a & 2010b). Here, the authors evaluate ozone concentration, exposure, and foliar injury data that have been collected at the very forest sites across Europe from approx. 200 plots and 20 countries. Emphasis will be put on European scale analyses for spatial and temporal trends for ozone concentration and AOT40 exposure. These harmonized and aggregated data sets will serve as a valuable basis for further integrated analyses and validation of models, such as from EMEP