Titre: The Creation of Emissions Data for Regional Models: Species Lumping and Reactivity Assumptions

Gas-phase emissions data are a crucial component of regional scale air-quality models. The emissions input are created using emissions processing systems, which produce a small number of model hydrocarbon emissions from a detailed database. Traditionally, the processing systems have been configured to preserved hydrocarbon reactivity, in order for the mdoel speciation to adequately simulate ozone formation. This results in the loss of a large amount of information relevant to the formation of primary and secondary organic aerosols. In addition, the mathematical technique by which reactivity is conserved is appropriate for time scales of several days, while shorter time scales may be more appropriate for ozone formation. This talk will describe the reconfiguration of the Canadian Emissions Processing System (CEPS) to preserve both reactivity and particulate forming potential in the emitted organic speciation. Estimates of the relative amounts of emitted VOCs expeceted to have a significant particulate component will be presented, for a domain, covering much of eastern North America. The mathematics of reactivity lumping, and the effects of assumed time scale on predicted emissions levels will also be discussed.