Impact of biogenic emissions on ozone and fine particles over Europe: Comparing effects of temperature increase and a potential anthropogenic NO x emissions abatement strategy

The impact of biogenic emissions on ozone and PM2.5 levels over Europe is assessed using CMAQ. Biogenic emissions are predicted to increase Max8hrO3 mixing ratios by 5.7% and to decrease PM2.5 concentrations by 1.9%, increasing PM2.5_OC by 13.6% and decreasing , and by 5.6%, 3.7% and 5.6%, respectively, on average over Europe due to their interactions with anthropogenic emissions. A suite of perturbations in temperature is imposed individually on the base case conditions in order to determine the sensitivities to air temperature changes. Temperature increases of 1, 2 or 3 degree K suggest an average increase in Max8hrO3 mixing ratios of 0.9%, 1.8% or 2.9%, respectively, and an average decrease in daily average PM2.5 concentrations of 2.5%, 4.2% and 5.8%, respectively, increasing PM2.5_OC and decreasing , and component concentrations on average over Europe. In order to examine if abatement measures for anthropogenic emissions could offset ozone increases in higher temperatures and their effect on PM2.5 concentrations, a simulation with a domain wide reduction in anthropogenic NO x emissions of 10% is performed. This is estimated to reduce Max8hrO3 mixing ratios by 1.3% on average over Europe. However, NO x reduction is estimated to increase Max8hrO3 in VOCs limited areas. The reduction in anthropogenic NO x emissions is predicted to reduce PM2.5 concentrations by 1.0% enhancing the reduction simulated, here, with temperature increase but further modifying PM2.5 component concentrations.