This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
The main objective of this project is to provide an improved fundamental understanding of the atmospheric aging cycle of organic aerosol derived from biogenic terpenoid and reduced organic nitrogen compounds through laboratory reaction chamber experiments on secondary organic aerosol (SOA) growth and processing. Key semi-volatile species that are direct precursors to SOA will be identified and SOA yields quantified for a wide variety of known biogenic and anthropogenic atmospheric emissions. A unique combination of online soft-ionization (photoelectron resonance capture ionization, PERCI) aerosol mass spectrometry (AMS) with gas chromatographic analysis will be used to directly measure the transformation of representative volatile terpenoid compounds to the aerosol phase. Similar experiments will investigate the sequestration of reduced nitrogen by organic aerosols and develop a more fundamental understanding of how this sequestration impacts SOA aging and growth as well as the role SOA has in the transport and deposition of reduced nitrogen.
Ultimately, the results from this work will provide detailed chemical mechanisms, product branching ratios, and SOA yields under a variety of atmospherically relevant oxidant mixtures, for a variety of compound classes, concentrations and relative humidities. This knowledge will be of interest both to a broad chemical audience regarding mixed phase chemical reaction mechanisms and also to the atmospheric community in terms of quantifying oxidative gas to particle transitions, a highly uncertain area of the field of atmospheric chemistry.
