Reactivity Scales as Comparative Tools for Chemical Mechanisms

Incremental ozone impacts or reactivities have been calculated for selected organic compounds using a Master Chemical Mechanism (MCMv3.1) and compared with those calculated elsewhere with the SAPRC-07 chemical mechanism. The comparison of incremental reactivities has been completed for 116 organic compounds representing the alkanes, alkenes, aldehydes, ketones, aromatics, oxygenates, and halocarbons. Both mechanisms have constructed a consistent and coherent description of reactivity within each class of organics. MCMv3.1 and SAPRC-07 have represented some features of the available body of understanding concerning the atmospheric oxidation of organic compounds in a consistent and quantitative manner, although significant differences were found for 14 organic compounds. These differences represent species-dependent facets of their atmospheric chemistry that have not been adequately resolved in the available literature experimental data.