AGGREGATION AND ANALYSIS OF VOLATILE ORGANIC-COMPOUND EMISSIONS FOR REGIONAL MODELING

A general two-step procedure for aggregating the hundreds of reported volatile organic compounds (VOCs) into a much smaller set of lumped classes appropriate for regional airshed modeling is described. In the first step, the compounds are condensed into a manageable number of emission categories which could be adapted to a variety of molecularly-based lumped chemical mechanisms. In the second step, the emissions are further aggregated into a smaller set of VOC classes which directly correspond to those in a particular model's mechanism. The application of this procedure is illustrated by aggregating the National Acid Precipitation Assessment Program (NAPAP) anthropogenic VOC emissions inventory the U.S. first into the 32-class system, and then into the groups of model species used in the latest version of the Regional Acid Deposition Model (RADM2.0). The importance of different VOC categories and source types on regional pollution production is explored by comparing the contributions of each of the emissions groupings, RADM model species, and major emissions sources, to total moles carbon VOC reacted in model simulations. For this particular anthropogenic inventory and chemical mechanism, it is found that over 50% of the moles carbon reacted is associated with mobile sources. Such analysis can help indicate which uncertainties in anthropogenic emissions inventories may have the greatest impact on results of regional simulations. © 1990.