HR: 17:00h
AN: A44A-05    [Abstracts]
TI: Factors Influencing Aerosol Formation in the Simulation of Alpha-pinene Oxidation Experiments
AU: * Muller, J
EM: jfm@aeronomie.be
AF: Belgian Institute for Space Aeronomy, Avenue Circulaire 3, Brussels, 1180, Belgium
AU: Compernolle, S
EM: stevenc@aeronomie.be
AF: Belgian Institute for Space Aeronomy, Avenue Circulaire 3, Brussels, 1180, Belgium
AU: Ceulemans, K
EM: karlc@aeronomie.be
AF: Belgian Institute for Space Aeronomy, Avenue Circulaire 3, Brussels, 1180, Belgium
AU: Vereecken, L
EM: Luc.Vereecken@chem.kuleuven.ac.be
AF: University of Leuven, Celestijnenlaan 200 F, Leuven, 3001, Belgium
AU: Peeters, J
EM: Jozef.Peeters@chem.kuleuven.ac.be
AF: University of Leuven, Celestijnenlaan 200 F, Leuven, 3001, Belgium
AB: A detailed model is presented for the oxidation of the monoterpene alpha-pinene and the associated formation of Secondary Organic Aerosols (SOA). It is based on a quasi-explicit mechanism for the oxidation of alpha-pinene down to the formation of primary products, developed on objective grounds using advanced quantum theoretical methods, and on a simplified representation for the further oxidation of the products. Gas/particle partitioning follows a kinetic representation with coefficients from vapor pressures calculated using a dedicated group contribution method. This model is evaluated against a large number of laboratory experiments. The simulated and observed SOA yields agree to within a factor of 2 in most cases. The role of known shortcomings in the degradation mechanism is discussed. The role of association reaction of aldehydes and hydroperoxides in the particle phase is also estimated, based on laboratory measurements for the (forward and backward) reaction rates in different solvents. These reactions are found to have a significant impact in several low-NOx ozonolysis experiments.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0317 Chemical kinetic and photochemical properties
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting