AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Real-Time Measurements of Water-Insoluble Fractions and Black Carbon Concentrations With Water and Butanol Based Particle Counters
DANIEL SHORT, Michael Giordano, Yifang Zhu, Andrea Polidori, Akua Asa-Awuku, University of California, Riverside
Abstract Number: 148 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Particle number and size information is important for anthropogenic combustion effects on air quality, climate, and health. The composition of particles from vehicular fuel combustion, may contain water insoluble black carbon (BC) and other insoluble material that modify particle nucleating properties. Conversely, the soluble fraction is important for particle water–uptake and wet deposition processes. Long Beach, California has heavy commercial traffic which includes the Port of Los Angeles as well as many freeways and railways.
For this study, ambient aerosol was sampled from the South Coast Air Quality Management District (SCAQMD) instrument station located 15 m from the I-710 freeway in Long Beach, California. A water-based condensation particle counter (CPC) and a butanol-based CPC provided particle number concentration data. Both instruments were coupled with a Scanning Mobility Particle Sizer (SMPS) and particle number and size were recorded. Our novel measurement and analysis technique exploits the differences in particle distributions from the CPCs to infer insoluble particle mass fractions from real-time emissions. The data is correlated with BC measurements obtained with a Multi-Angle Absorption Photometer (MAAP). The contribution of insoluble mass from insoluble BC is determined. These differences show that the presence of BC has a significant effect on the particle activation ability of water-based CPCs at diameters below 30nm. Real-time insoluble mass fractions are presented.