Modeling Source Contributions to Submicron Particle Number Concentrations Measured in Rochester, New York
Abstract:An advanced receptor model was used to elicit source information based on ambient submicron (0.01-0.47 m) particle number concentrations, gaseous species, and meteorological variables measured at the New York State Department of Environmental Conservation central monitoring site in Rochester, NY. Four seasonal data sets (winter, spring, summer, and fall) were independently investigated. A total of ten different sources were identified, including two traffic factors, two nucleation factors, industrial emissions, residential/commercial heating, secondary nitrate, secondary sulfate, ozone-rich secondary aerosol, and regionally transported aerosol. The resolved sources were generally characterized by similar number modes for either winter, spring, summer or fall. The size distributions for nucleation were dominated by the smallest particles (<10 -30 nm) that gradually grew to larger sizes as could be seen by observing the volume profiles. In addition, the nucleation factors were closely linked to traffic rush hours suggesting that cooling of tail-pipe emissions may have induced nucleation activity in the vicinity of the highways. Although the diurnal pattern of each of the two traffic factors closely followed traffic rush hour for Rochester, their size modes were different suggesting that these factors might represent local and remote emissions. Industrial emissions were dominated by emissions from coal-fired power plants that were located to the northwest of the sampling site. These facilities represent the largest point emission sources of SO2, and probably ultrafine (<0.1 m) or submicron particles, in Rochester. Regionally transported material was characterized by accumulation mode particles. Air parcel back-trajectories showed transport of air masses from the industrial midwest.
Document Type: Research Article
Affiliations: 1: Department of Chemical and Biomolecular Engineering, Clarkson University, Potsdam, NY, USA 2: Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA
Publication date: February 1, 2007