HR: 16:50h
AN: A22G-04    [PDF]
TI: Studies of the HO$_{2}$ + C$_{2}$H$_{5}$O$_{2}$ and C$_{2}$H$_{5}$O$_{2}$ + C$_{2}$H$_{5}$O$_{2}$ Reactions Using Near-IR Kinetic Spectroscopy
AU: * Alconcel, L S
EM: Leah.Alconcel@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive M/S 183-901, Pasadena, CA 91109-8099 United States
AU: Robichaud, D J
EM: David.J. Robichaud@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive M/S 183-901, Pasadena, CA 91109-8099 United States
AU: Okumura, M
EM: mo@its.caltech.edu
AF: California Institute of Technology, 1200 E. California Boulevard M/S 127-72, Pasadena, CA 91125 United States
AU: Sander, S P
EM: Stanley.P.Sander@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive M/S 183-901, Pasadena, CA 91109-8099 United States
AB: It is well known that hydroperoxy (HO$_{2}$) and alkylperoxy (RO$_{2}$) radicals participate in cycles that produce tropospheric ozone from photochemical hydrocarbon oxidation. Kinetic data for the reactions of these species are often contradictory or insufficient. In this study, the temperature and pressure dependencies of the hydroperoxy and ethylperoxy cross-reaction and the ethylperoxy self-reaction rates will be reported. The self-reactions of alkylperoxy radicals leads to the secondary formation of hydroperoxy radicals and hence competing self- and cross-reactions. Simultaneous monitoring of the hydroperoxy radical signal via near-IR frequency modulation (FM) spectroscopy and the ethylperoxy radical signal via UV absorption spectroscopy permits unique characterization of the peroxy species. This technique, when used to measure the rate constants under a range of conditions, will aid in understanding the complex alkylperoxy radical chemistry. The rate constant measurements provided by this study will represent a significant step towards generating more accurate atmospheric models, particularly for the remote troposphere, where NO is not the dominant sink for alkylperoxy radicals.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0317 Chemical kinetic and photochemical properties
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting