Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach B. Aumont1, S. Szopa1,*, and S. Madronich2 1Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Universités Paris 7 et Paris 12, 94010 Créteil Cedex, France 2National Center for Atmospheric Res., Atmospheric Chemistry Division, P.O. Box 3000, Boulder, Colorado 80307, USA *now at: Laboratoire des Sciences du Climat et de l’environnement, UMR CNRS CEA 1572, 91191 Gif-sur-Yvette, France
Abstract. Organic compounds emitted in the atmosphere are oxidized in complex reaction
sequences that produce a myriad of intermediates. Although the cumulative
importance of these organic intermediates is widely acknowledged, there is
still a critical lack of information concerning the detailed composition of
the highly functionalized secondary organics in the gas and condensed phases.
The evaluation of their impacts on pollution episodes, climate, and the
tropospheric oxidizing capacity requires modelling tools that track the
identity and reactivity of organic carbon in the various phases down to the
ultimate oxidation products, CO and CO2. However, a fully detailed
representation of the atmospheric transformations of organic compounds
involves a very large number of intermediate species, far in excess of the
number that can be reasonably written manually. This paper describes (1) the
development of a data processing tool to generate the explicit gas-phase
oxidation schemes of acyclic hydrocarbons and their oxidation products
under tropospheric conditions and (2)
the protocol used to select the reaction products and the rate constants.
Results are presented using the fully explicit oxidation schemes generated
for two test species: n-heptane and isoprene. Comparisons with
well-established mechanisms were performed to evaluate these generated
schemes. Some preliminary results describing the gradual change of organic
carbon during the oxidation of a given parent compound are presented.
Citation: Aumont, B., Szopa, S., and Madronich, S.: Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach, Atmos. Chem. Phys., 5, 2497-2517, doi:10.5194/acp-5-2497-2005, 2005.