Measurements and Modeling of Vehicle Cold Start Emissions Webinar
- Measurements and Modeling of Vehicle Cold Start Emissions
Dr. Serena Chung and Dr. Tom Jobson
- Department of Civil and Environmental Engineering
- Washington State University
Exposure to vehicle exhaust emissions is a major cause of cardiovascular disease and a cancer risk factor. Vehicle emissions models, such as the US EPA’s Motor Vehicle Emissions Simulator (MOVES) suggest that in cold climates, the majority of pollutant mass emitted by vehicles occurs during engine cold starts and idling and not when the vehicle is moving along the road. In winter, cold starts in combination with meteorological conditions that trap vehicle emissions under low lying temperature inversions lead to significantly elevated pollutant concentrations; thus, people living in colder climates are potentially exposed to significantly higher concentrations of air toxics than in warmer climates because of the combination of high cold start and idling emissions and lower dispersion rates. However vehicle emissions data for cold climates is sparse and the accuracy of vehicle emissions model parameterizations for cold climates is not known. In this work, we use measurements and modeling to measure chemical composition of cold start emissions and to evaluate the temperature dependence of cold start emissions. We use high time resolution measurements of carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs) to measure pollutant mass emitted during engine cold starts from gasoline and diesel engine vehicles. In addition, we use the EPA’s MOVES model for estimates of the contribution of emissions during cold starts to total vehicle emissions for Yakima County, Washington and to generate temperature dependence curves for cold start emissions. This work lays the foundation to evaluate and improve MOVES’ ability to simulate cold start emissions and their impact on air quality.
Dr. Serena Chung is an Associate Research Professor in the Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, at Washington State University. Her research focuses on developing, improving, and applying models to better understand the physical and chemical processes that affect air quality and its interaction with climate. Depending on the scientific objectives, the models she uses range from processed-based box models to three-dimensional regional and global chemistry and climate models. In the last few years, Dr. Chung has been involved in the development and operation of the regional air quality forecasting system for Pacific Northwest (PNW) called AIRPACT, which has been a widely used tool for federal, state and local agencies in the PNW in managing air quality concerns. Dr. Chung received a B.S. in Chemical Engineering from University of Illinois at Urbana Champaign and a M.S. and Ph.D. in Chemical Engineering from California Institute of Technology.
Dr. Tom Jobson is a Professor in the Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, at Washington State University. His current research interests focus on the atmospheric chemical processing of hydrocarbons emitted from vehicles, including measuring vehicle emission rates, performing field experiments to improve our understanding of the impact of vehicle emissions on air quality, and investigating the use of photoactive catalysts in paving materials to mitigate roadway pollution. Dr. Jobson received a B.Sc. in Chemistry from the University of Victoria and a Ph.D. in chemistry form York University in Toronto.