Compilation and evaluation of a Paso del Norte emission inventory

Emission inventories of ozone precursors are routinely used as input to com prehensive photochemical air quality models. Photochemical model performanc e and the development of effective control strategies rely on the accuracy and representativeness of an underlying emission inventory. This paper desc ribes the tasks undertaken to compile and evaluate an ozone precursor emiss ion inventory for the El Paso/Ciudad Juarez/Southern Dona Ana region. Point , area and mobile source emission data were obtained from local government agencies and were spatially and temporally allocated to a gridded domain us ing region-specific demographic and land-cover information. The inventory w as then processed using the US Environmental Protection Agency (EPA) recomm ended Emissions Preprocessor System 2.0 (UAM-EPS 2.0) which generates emiss ions files compatible with the Urban Airshed Model (UAM). A top-down evalua tion of the emission inventory was performed to examine how well the invent ory represented ambient pollutant compositions. The top-down evaluation met hodology employed in this study compares emission inventory ratios of non-m ethane hydrocarbon (NMHC)/nitrogen oxide (NOx) and carbon monoxide (CO)/NOx ratios to corresponding ambient ratios. Detailed NMHC species comparisons were made in order to investigate the relative composition of individual hy drocarbon species in the emission inventory and in the ambient data. The em ission inventory compiled during this effort has since been used to model o zone in the Paso del Norte airshed (Emery et at., CANx modeling of ozone an d carbon monoxide in the Paso del Norte airshed. In: Proc of Ninety-Third A nnual Meeting of Air & Waste Management Association, 18-22 June 2000, Air & Waste Management Association, Pittsburgh, PA, 2000). (C) 2001 Elsevier Sci ence B.V. All rights reserved.