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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Poster 1: Rethinking Emissions Inventories: Theory, Innovation, and Practice Within the Southern Oxidants Study
Ellis Cowling1, Carlos Cardelino2, and Cari Furiness1
1 North Carolina State University, Raleigh, NC;
2 Georgia Institute of Technology, Atlanta, GA
Since its inception in 1988, scientists and engineers within the Southern Oxidants Study have been systematically rethinking the assumptions that have undergirded US policies for management of ozone and particulate matter pollution. We believe that cost-effective management of air pollution can only be achieved if management plans are based on amounts of precursors actually present in the air rather than on amounts of precursors believed to be present on the basis of emissions inventories. EPA publication AP-42 and, more recently, the Emissions Inventory Improvement Program (EIIP) have been important sources of guidance for development of emissions inventories.
The prevalent policy assumption has been that decreases in emissions of anthropogenic precursors, mainly in counties designated to be part of a given non-attainment area should be sufficient to bring the area into compliance with the standard. EPA requires that states use emissions-based mathematical models (the Urban Airshed Model has been preferred) to make an “attainment demonstration” for a “model episode” under “extreme weather conditions” that were expected to provide an “an adequate margin of safety” for the health of people and welfare of ecosystems within the non-attainment area.
Weaknesses in emissions inventories have always been one of the largest sources of worry about the adequacy of this theory and the veracity of these policy assumptions. Thus, during the past 14 years, SOS scientists developed, used, and promoted a series of innovative approaches to evaluate and improve emissions inventories and the ways inventory information is used in state implementation plans.
These innovations have included: 1) Important parts of the Biogenic Emissions Inventory System (BEIS) for isoprene emissions from hardwood (especially oak) forests, terpene emissions from coniferous forests, and NO emissions from well-fertilized row-crop and pasture lands; 2) NO emissions from lightning strikes; 3) Increased use of traffic counters, remote sensing methods, tunnel studies, information on street and highway grades, and the phenomena of “power enrichment” during acceleration and on heavy grades in estimating VOC and NO emissions from motor vehicles; 4) Use of fuel sales statistics as a check on VOC, NO , and CO emissions from motor vehicles, off-road construction equipment, aircraft, railroads, pleasure boats, commercial shipping, and equipment powered by small internal combustion engines; 5) CO, VOC, and NO emissions from biomass burning in incinerators, pulp and paper mills, controlled burning of crop and forest residues, highway construction sites, and burning of downed timber following hurricanes, ice storms, and other extreme weather events, 6) CO emissions from wild fires within nearby and regional urban, suburban, and rural areas, 7) CO emissions from wildfires in far-distant locations in the US, Canada, and Mexico; 8) Inverse modeling of VOC and NO emissions; 9) Use of survey data to determine ozone sensitivity to point sources; 10) Influence of isoprene emissions in regional ozone modeling, 11) Differences in ozone production efficiency of NO emissions from large and small power plants; 12) Methane and CO contributions to ozone production in the Nashville/Middle Tennessee Ozone Study, 13) Emissions of ethene, propene, and other light alkenes from petroleum processing facilities in the Houston-Galveston areas of Texas, 14) Ammonia emissions from animal feeding operations, fertilizer applications, industries and motor vehicles; 15) Effectiveness of regulatory practices that distinguish “reactive” from “negligibly reactive” VOCs and then exclude “negligibly reactive” VOCs from ozone and PM2.5 precursor inventory requirements; 16) Evaluating emissions inventories using air concentration measurements from towers, tall buildings, tethered balloons, and aircraft; 17) Changes in the ratio of NO to VOC emissions as a result of changes in fuels used in motor vehicles; and 18) Relative importance of local area sources, nearby point sources, regional background sources, and far-distant remote sources.