HR: 0800h
AN: A11A-0045    [Abstracts]
TI: An examination of oxidant amounts on secondary organic aerosol formation and aging
AU: * Chen, Z
EM: zxc11@psu.edu
AU: Ren, X
EM: xur1@psu.edu
AU: Brune, W H
EM: brune@meteo.psu.edu
AB: The effect of HO_x radicals (OH and HO₂) and ozone (O₃) on secondary organic aerosol (SOA) formation and aging has been studied. Experiments were performed in the presence and in the absence of oxygen in a small chamber (~18 liters) for several organic precursor gases, including m-xylene, alpha-pinene and ethylbenzene. The HO_x source was the UV photolysis of humidified air or nitrogen and was measured with the Penn State GTHOS (Ground-based Tropospheric Hydrogen Oxides Sensor). The precursor gases concentration was monitored with an online GC-FID. The aerosol mass was then quantified by a Tapered Element Oscillating Microbalance (TEOM). Typical oxidant mixing ratios were (0.??? -10) ppm for O₃, (10-400) pptv for OH and (0.1-4) ppb for HO₂. The SOA yields for different oxidant conditions will be discussed.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting