Atmospheric Oxidation: Mechanism and Kinetics of the Reaction of the Pinene-Derived Species, Campholenic Aldehyde

Science Center, Bent Corridor

Pinene is the second most abundant biogenic non-methane hydrocarbon present in the atmosphere. This volatile bicyclic alkene, produced mainly by coniferous trees, undergoes gas phase reactions to form epoxide intermediates. The oxidation of α-pinene to the epoxide α-pinene oxide is related to both tropospheric ozone and secondary organic aerosol (SOA) formation, and thus linked to issues of air pollution and global climate change. We are interested in determining the mechanism and rate constants for the reactions of atmospherically relevant α-pinene aldehyde derivatives with OH radicals. Specifically, we have investigated the daytime OH radical initiated process for the α-pinene aldehyde derivative, campholenic aldehyde, using our lab's unique flow tube chemical ionization mass spectrometer (FT-CIMS). These measurements show that the radical reaction occurs on an atmospherically relevant time scale, and thus the reaction will have a significant effect on the production of tropospheric ozone and SOA.