AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Lab-in-the-Field Perturbation Experiments: SOA Formation in an Ambient Matrix
JEAN RIVERA-RIOS, Adam Wright, Nga Lee Ng, Georgia Institute of Technology
Abstract Number: 349 Working Group: Urban Aerosols
Abstract The oxidation of volatile organic compounds (VOC) in the atmosphere leads to the formation of secondary pollutants like ozone and secondary organic aerosol (SOA). Traditional chamber experiments have been used extensively as the main tool to study SOA yields from many VOCs. However, the formation of SOA from a VOC has been shown to depend on not only the identity of the VOC but also, the oxidant, oxidant concentration, peroxy-radical fate and the concentrations of other VOCs during oxidation. Laboratory chamber studies typically push the reaction regimes to an extreme to simplify the chemistry, though recent studies have pointed to the importance of studying how different reaction parameters interact. In order to study matrix effects on SOA formation, we built an outdoor chamber in which specific VOCs are oxidized using ambient air as the matrix. A state-of-the-art instrumentation suite is employed in order to understand which variables have the strongest effect on SOA formation from VOCs and their oxidation products. In addition, the formed SOA is analyzed using positive matrix factorization in order to understand the sources of different organic aerosol factors found in ambient data. The results from these experiments can provide improved parametrizations for modeling SOA under realistic conditions.