Effect of Elevated Ammonia Concentrations on Secondary Organic Aerosol Formation during the Georgia Tech Ambient Field Study in Yorkville, Georgia
AIChE Annual Meeting
Monday, November 14, 2016 - 10:00am to 12:30pm
A suite of instruments was deployed to characterize gas and particle phase compositions over the period of the study. A Scanning Mobility Particle Sizer (SMPS) spectrometer consisting of a Differential Mobility Analyzer (DMA) and Condensation Particle Counter (CPC) was used to determine the concentration and particle size distribution of ambient aerosol particles in the size range of 10-300 nm. Additionally, a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was used to determine the chemical composition of sub-micron non-refractory aerosol. Aerosol mass concentration was found to be relatively constant with slight diurnal variation. The particle size distribution for number concentration showed significant variation between day and night and revealed numerous nighttime growth events. The SMPS data were compared to AMS data to determine the chemical species present during episodes of high aerosol loading and growth events. Meteorological measurements from nearby SEARCH instruments were used to determine potential factors affecting mass concentration. From these and future results, the formation of SOA in the presence of elevated ammonia concentration will be evaluated.