Atmospheric Oxidation Mechanism of Isoprene

The atmospheric oxidation mechanism of isoprene initiated by OH, O-3, NO3, and Cl, which incorporates the most recent laboratory and theoretical studies, is described. A box model intercomparison between the new mechanism and previous available isoprene oxidation mechanisms has been performed. Ozone and OH concentrations are compared with predictions by the previous mechanisms in high and low NO, scenarios. The O-3 and OH sensitivities to the chlorine-isoprene reactions have also been investigated by comparing the box model results with and without the chlorine-isoprene reactions, showing that the ozone production rate and OH concentrations are slightly impacted. The new mechanism facilitates more accurate modelling of isoprene photochemistry in the atmosphere.