Bourns Hall

Colloquium

Dr. Jana B. Milford Associate Professor Department of Mechanical Engineering University of Colorado at Boulder Uncertainty in Photochemical Air Quality Modeling Abstract Atmospheric chemistry and transport models are important tools for both research and policy analysis of control strategies for ozone and particulate matter. This seminar will discuss our work on understanding uncertainties in these models, including formal uncertainty quantification using Bayesian Monte Carlo (BMC) techniques and use of stochastic optimization to investigate optimal control strategies under uncertainty. The seminar will also describe our current collaborative work on improving estimates of biogenic volatile organic compound (BVOC) contributions to secondary organic aerosols. Bayesian Monte Carlo analysis provides a means of combining subjective “prior” uncertainty estimates developed by standard Monte Carlo techniques, with information about a model’s performance in comparison to observations. To demonstrate this approach, BMC has been applied to air quality model predictions of ozone concentrations in Southern California. The effect of uncertainties in the model on estimates of least-cost control strategies for ozone is also illustrated. To estimate the contributions of BVOC to secondary organic aerosols, new data on emissions of monoterpenes and sesquiterpenes are being acquired and incorporated into the Model of Exchange of Gases between the Atmosphere and Nature (MEGAN). In turn, MEGAN is being used to provide biogenic emissions inventories for the Community Multiscale Air Quality Model (CMAQ). Biosketch Jana Milford is an Associate Professor of Mechanical Engineering at the University of Colorado and Senior Scientist and Staff Attorney at Environmental Defense, in Boulder, CO. She holds a Ph.D. in Engineering and Public Policy from Carnegie Mellon University and a J.D. from the University of Colorado School of Law. She is co-author, with Anu Ramaswami and Mitchell Small, of a new textbook entitled “Integrated Environmental Modeling: Pollutant Transport, Fate, and Risk in the Environment (Wiley, 2005). Wednesday, June 1, 2005 10:10 a.m. - 11:00 a.m. A265 Bourns Hall (Refreshments will be served at 10:00 a.m.)