9629577 Paulson Alkenes are important chemical species for the formation of oxidizing compounds within the troposphere. On a global scale, alkenes comprise the majority of non-methane hydrocarbon emissions, and roughly half of the carbon that reacts through an ozone-alkene chemical reaction, does so by forming short-lived Criegee reaction intermediates. The research supported by this award is expected to make significant contributions to the understanding of the mechanism of ozone-alkene reactions in the troposphere, especially those involving photochemical reactions of biogenic alkenes with tropospheric ozone. The project examines the kinetics and mechanism of ozone-alkene reactions using Teflon batch reactors in conjunction with GC/FID/MS, gas phase FTIR spectroscopy and FTIR/matrix isolation analytical techniques. The experimental approach focuses on the decomposition and reaction pathways of Criegee reaction intermediates. Study of the chemical reaction mechnisms involving Criegee intermediates has important possibilities for understanding the processes that control the formation of oxidants in the troposphere. Overall, the goals described in the research project would lead to a significant improvement of our understanding of atmospheric reactions involving alkenes, and hence of air pollution and tropospheric chemistry. ATM-9629353
