Heatwaves are often associated with elevated surface ozone concentrations due to the combined effects of favourable meteorological conditions, enhanced photochemical activity, and increased emissions of biogenic volatile organic compounds (BVOCs). However, the contribution of BVOCs to ozone formation varies considerably across Europe, depending on vegetation characteristics, meteorological conditions, anthropogenic emissions, and atmospheric chemical regimes.

The European heatwave and ozone pollution episode of July 2022 was investigated within the EMEP Task Force on Measurements and Modelling (TFMM) model intercomparison exercise. The scope and methodology of the exercise will be presented, followed by an overview of the modelling results, with particular emphasis on regional differences in the contribution of biogenic VOC emissions to surface ozone concentrations. Uncertainties in the simulated impact of BVOC emissions on ozone will be assessed based on differences between the participating models. Preliminary results of model performance evaluation for individual VOC species, including isoprene, will also be presented.

Other challenges related to ozone modelling, including uncertainties in BVOC emissions and the impact of European wildfires on ozone formation, will be briefly discussed.