Analysis of air quality data near roadways using a dispersion model |
| |
| Authors: | Akula Venkatram Vlad Isakov Eben Thoma Richard Baldauf |
| |
| Institution: | 1. University of California, Riverside, CA 92521, USA;3. U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, USA;4. U.S. Environmental Protection Agency, Office of Air and Radiation, Office of Transportation and Air Quality, Ann Arbor, MI 48105, USA;1. University of Pittsburgh Graduate School of Public Health, Department of Environmental and Occupational Health, Pittsburgh, PA, United States;2. University of Wisconsin–Green Bay, Department of Natural and Applied Sciences (Statistics), Green Bay, WI, United States;3. Colorado State University, Center for Energy Development and Global Health, Fort Collins, CO, United States;1. U.S. Environmental Protection Agency, Office of Research and Development, 109 Alexander Drive, Research Triangle Park, NC 27713, USA;2. University of North Carolina Institute for the Environment, Chapel Hill, NC 27599, USA;3. University of California Riverside, Bourns College of Engineering, Riverside, CA 92521, USA;4. U.S. Environmental Protection Agency, Office of Transportation and Air Quality, 2000 Traverwood Drive, Ann Arbor, MI 48105, USA;1. Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, China;2. Department of Civil and Environmental Engineering, University of Southern California, CA, USA;3. Department of Chemistry, University of Cambridge, Cambridge, UK;1. University of California, Riverside, CA 92521, USA;2. U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Research Triangle Park, NC 27711, USA;3. U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, USA |
| |
| Abstract: | We used a dispersion model to analyze measurements made during a field study conducted by the U.S. EPA in July–August 2006, to estimate the impact of traffic emissions on air quality at distances of tens of meters from an eight-lane highway located in Raleigh, NC. The air quality measurements consisted of long path optical measurements of NO at distances of 7 and 17 m from the edge of the highway. Sonic anemometers were used to measure wind speed and turbulent velocities at 6 and 20 m from the highway. Traffic flow rates were monitored using traffic surveillance cameras. The dispersion model Venkatram, A., 2004. On estimating emissions through horizontal fluxes. Atmospheric Environment 38, 2439–2446] explained over 60% of the variance of the observed path averaged NO concentrations, and over 90% of the observed concentrations were within a factor of two of the model estimates.Sensitivity tests conducted with the model indicated that the traffic flow rate made the largest contribution to the variance of the observed NO concentrations. The meteorological variable that had the largest impact on the near road NO concentrations was the standard deviation of the vertical velocity fluctuations, σw. Wind speed had a relatively minor effect on concentrations. Furthermore, as long as the wind direction was within ±45° from the normal to the road, wind direction had little impact on near road concentrations. The measurements did not allow us to draw conclusions on the impact of traffic-induced turbulence on dispersion. The analysis of air quality and meteorological observations resulted in plausible estimates of on-road emission factors for NO. |
| |
| Keywords: | Air quality Line source Dispersion modeling Traffic emissions Mobile sources |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
