AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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Single Particle Characterization of Carbonaceous Aerosol using Soot-Particle Aerosol Mass Spectrometer (SP-AMS)
ALEX K. Y. LEE, Megan Willis, Jonathan Abbatt, University of Toronto
Abstract Number: 180 Working Group: Single Aerosol Particle Studies - Techniques and Instrumentation
Abstract Black carbon (BC) aerosol can play a critical role influencing regional air quality, human health, and global climate. Fossil fuel combustion and biomass burning such as forest fires are the primary sources of ambient BC. Most BC particles are internally mixed with co-emitted organics and/or secondary organic materials produced via atmospheric processing, modifying the physical and chemical properties of the particles and their fate and environmental impacts. A real-time analytical technique with a single particle detection capability is an ideal approach to quantify the mixing state of ambient BC particles. However, quantification of a tiny amount of single particle material at the femtogram level is a considerable analytical challenge. The primary objective of this presentation is to demonstrate the single particle characterization capability of the Aerodyne Soot-Particle Aerosol Mass Spectrometer (SP-AMS) based on our recent observations in the field. The instrument was deployed in an urban environment to determine the mixing state of BC-containing particles from traffic-dominated emissions and the results were used to drive a particle-resolved aerosol box model to assess the effect of accurately representing BC mixing states on aerosol optical properties. Furthermore, we observed non-uniform mixing of particles within a biomass-burning plume in terms of molecular weight. Our results illustrate that high molecular weight organics can be a key contributor to low-volatility brown carbon observed in biomass-burning organic aerosol (BBOA). Lastly, preliminary results of aircraft measurements in the High Arctic will be discussed.