Modeling potential ozone impacts from natural hydrocarbons—I. Development and testing of a chemical mechanism for the nox-air photooxidations of isoprene and α-pinene under ambient conditions

Abstract

A chemical mechanism has been developed to predict O3 formation in mixtures of isoprene, α-pinene and NOx in air. The mechanism was tested against 17 outdoor smog chamber data sets from the University of North Carolina chamber and was shown to predict maximum O3 concentrations within ±20%. Reasonably good agreement was found between the predicted and measured time-concentration profiles of other species such as NO2, peroxyacetyl nitrate (PAN) and aldehydes. Due to the greater availability of kinetic and mechanistic data for isoprene and to the more extensive comparison of this mechanism to experimental data, the mechanism is considered more reliable for isoprene than α-pinene.