Photochemical ozone creation potentials for organic compounds in northwest Europe calculated with a master chemical mechanism

Master Chemical Mechanism containing over 2400 chemical species and over 7100 chemical reactions is employed here to describe the atmospheric degradation of 120 organic compounds and the associated regional scale ozone and PAN formation under conditions appropriate to the polluted boundary layer over northwest Europe. Photochemical ozone and PAN creation potentials (POCP and PPCP) are derived for each organic compound from their propensities to form ozone and PAN relative to ethylene and propylene, respectively. The robustness of these POCP values to changes in the NOx emission densities across Europe is tested and the values are compared with previous studies. The POCP values are reviewed and rationalised against the background of our current understanding of the intrinsic properties of each organic compound, their atmospheric degradation pathways and other mechanistic data. These POCPs should assist policy-makers in defining realistic and robust pollution control strategies which focus on those organic compounds which contribute most to regional scale ozone formation across northwest Europe.