The focus of this project is to investigate the yields of secondary organic aerosol (SOA) in an environmental chamber as a function of VOC/NOx levels and oxidant exposure. SOA formed from the OH oxidation of organic precursors happens mostly during the daytime. However, NO3 radicals are abundant at night. These elevated NO3 levels can also coincide with elevated levels of VOCs/IVOCs due to lower nighttime boundary layer heights, which may result in significant nighttime SOA formation. The chamber results will be used to model the underlying oxidation mechanisms and to relate them to atmospheric photochemical processes.
This research will provide new insight into the formation of secondary organic particles in the atmosphere and the oxidative aging of these particles. The results are important for understanding how aerosols influence the cooling and heating of the atmosphere and alter climate.