Abstract View
The Impact of Temperature on Organic Peroxy Radical Isomerization and Aerosol Production
NADIA TAHSINI, Matthew Goss, Jesse Kroll, MIT
Abstract Number: 74
Working Group: Aerosol Chemistry
Abstract
Organic peroxy radicals (RO2) are formed in the oxidation of nearly every hydrocarbon emitted into the atmosphere, and their subsequent chemistry plays a major role in radical cycling and the formation of secondary pollutants. While some RO2 pathways are well known, in general their reactivity in low-NOx conditions remains poorly constrained. Unimolecular RO2 isomerization, which produces highly oxygenated organic molecules (HOMs), remains a particularly challenging pathway to elucidate due to competition with the bimolecular reactions. Here, we study the formation and transformation of products from the low-NOx oxidation of large hydrocarbons in chamber experiments as a function of temperature. Product characterization is accomplished with mass spectrometric measurements, namely an Aerosol Mass Spectrometer (AMS) to characterize the amount and composition of aerosol formed under a given set of conditions. These results, coupled with simulations using the Master Chemical Mechanism (MCM) with the Framework for 0-D Atmospheric Modeling (F0AM), provide insight into the temperature sensitivity of RO2 isomerization, and more generally to the role that isomerization plays in aerosol formation.