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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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Comparison of Emissions Processing Systems and Emissions Inventories used for Houston-Galveston Air Quality Studies
Daewon W. Byun and Soontae Kim
Institute for Multidimensional Air Quality Studies
University of Houston, Houston, TX 77204
An emissions inventory (EI) is one of the essential data for air quality modeling. Prior to use in model simulations, the EI must be processed and converted into the suitable data formats accepted by air quality models (AQMs) such as CAMx and CMAQ. Since the model simulations using different EIs may result in significantly different pollutant concentrations for the same episode, it is important to compare emissions inventories currently used with such studies. Furthermore, even the same EI processed with different emission processing systems may present different model-ready emissions data. They depend on the methodologies of spatial and temporal allocations and speciation methods used in the emission processing systems, such as Emissions Preprocessing System (EPS2) and the Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system.
To study air quality in the Houston-Galveston Area (HGA), Texas Commission of Environmental Quality (TCEQ) has prepared the more updated Texas Emissions Inventory, which has been processed with EPS2. In order to utilize the Texas EI with other air quality models, we have processed the EI with SMOKE using a set of computer codes and quality assurance procedures in the Texas Emissions Inventory Preparation System (TEIPS). One of the key benefits of using SMOKE system is that it allows easy extension of the chemical mechanisms permitting investigation of the effects of the specific chemical components on the ozone production. With some additional efforts, the SMOKE system can be extended to include speciated particulate emissions and air toxics species. In this study, we compare emissions inventories available for Houston-Galveston air quality studies, for example, the Texas EI, NET96 and NEI99 processed with EPS2 and SMOKE, respectively.