Effects of Using Two Different Biogenic Emission Models on Ozone and Particles in Europe

In this paper, we discuss the importance of biogenic volatile organic compound (BVOC) emissions used in air quality simulations and how the model results are affected by the choice of the BVOC emission model. The European air quality in 2011 was simulated using CAMx regional air quality model with two different BVOC emission models: PSI-model and MEGAN. Especially isoprene and monoterpene emissions calculated by the two models differed significantly both in amounts and their spatial distribution. In general, MEGAN produced much higher isoprene emissions while PSI-model generated more monoterpene emissions. The difference in emissions between the two models was shown to be as high as a factor of 3 in summer. The choice of the BVOC emission model had significant consequences especially on the formation of organic aerosols as well as on ozone and inorganic aerosols. Using MEGAN led to relatively higher ozone concentrations in summer while much more SOA (secondary organic aerosol) was formed when PSI-model was applied. Our results suggest that the amount and spatial distribution of BVOC emissions might affect the oxidant concentrations (OH and nitrate radicals, ozone) leading to significant differences in SOA, ozone, particulate nitrate and sulfate concentrations calculated by different BVOC emission models.