9613729 Russell The major focus of this proposal is to develop a computationally effective sensitivity analysis technique for use in multidimensional air quality models, and to apply that technique to the border region between the US and Mexico. As part of that application, the research will quantify source impacts and develop sensitivity coefficients for various model parameters (e.g. deposition velocities and chemical rate constants). Because of its climate and rapid growth and industrialization, the Mexico-southwestern United States border area experiences elevated levels of ozone exceeding the national standards of the two countries. Addressing this air quality problem in the region is of particular interest for several reasons: first, the international nature of the problem, and the expected trans boundary pollutant flow, along with recent trade agreements (e.g. NAFTA and Maquiladoras); second, the high population growth in the area; and, third, the level of controls which differ widely between the various regions. If one can adequately demonstrate the source-air quality relationships through the application of sensitivity analysis, it is possible to develop much more cost effective integrated strategies for air pollution control in the region. It is proposed to develop a computationally attractive sensitivity analysis technique for use in multidimensional air quality models based on the direct decoupled sensitivity method. The resulting method will be designed and constructed in such a way as to be easily transportable between air quality models that are in common application today, and are being developed for future use. Furthermore, the system will make use of parallel computing environments. The method will be applied to air quality modeling along the Mexico-southwestem U.S. border to better understand pollutant dynamics in that region, and to quantify the model responses to inputs and model parameters. Finally, as an example of the power and uses of such techniques, the method will be applied to address three specific issues of importance in air quality engineering of interest in that region: explore the use of formal sensitivity analysis for model evaluation and intercomparison, quantify how ozone concentrations respond to emissions of various compounds and sources, and to further explore the use of sensitivity analysis in studying volatile organic compound (VOC) reactivity scales. The expected results from this project are: development of a computationally efficient sensitivity method for air quality modeling; application of the sensitivity analysis method along the Mexico-U.S. border to better understand the dynamics of air pollutants in that region, assessment of model sensitivities and uncertainties in the application along the border region, and a growing relationship between Georgia Tech and Instituto Technologico Estudios Superiores de Monterrey (ITESM) due both to the direct collaboration between the two principal investigators, but also due to the advanced education of a Mexican student (from ITESM) at Georgia Tech.
