title: The Reaction between CH3O2and OH Radicals: Product Yields and Atmospheric Implications.
abstract: The reaction between CH3O2and OH radicals has been shown to be fast and to play an appreciable role for the removal of CH3O2radials in remote environments such as the marine boundary layer. Two different experimental techniques have been used here to determine the products of this reaction. The HO2yield has been obtained from simultaneous time-resolved measurements of the absolute concentration of CH3O2, OH, and HO2radicals by cw-CRDS. The possible formation of a Criegee intermediate has been measured by broadband cavity enhanced UV absorption. A yield of ϕHO2= (0.8 ± 0.2) and an upper limit for ϕCriegee= 0.05 has been determined for this reaction, suggesting a minor yield of methanol or stabilized trioxide as a product. The impact of this reaction on the composition of the remote marine boundary layer has been determined by implementing these findings into a box model utilizing the Master Chemical Mechanism v3.2, and constraining the model for conditions found at the Cape Verde Atmospheric Observatory in the remote tropical Atlantic Ocean. Inclusion of the CH3O2+OH reaction into the model results in up to 30% decrease in the CH3O2radical concentration while the HO2concentration increased by up to 20%. Production and destruction of O3are also influenced by these changes, and the model indicates that taking into account the reaction between CH3O2and OH leads to a 6% decrease of O3.
authors.affiliation: Université Lille, CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Assaf
authors.affiliation: Combustion Research Facility, Sandia National Laboratories , 7011 East Ave., Livermore, California 94551 United States.
authors.forename: Leonid
authors.initials: L
authors.lastname: Sheps
authors.affiliation: School of Chemistry, University of Leeds , Woodhouse Lane, Leeds, LS2 9JT, U.K.|National Centre for Atmospheric Chemistry, University of Leeds , Woodhouse Lane, Leeds, LS2 9JT, U.K.
authors.forename: Lisa
authors.initials: L
authors.lastname: Whalley
authors.affiliation: School of Chemistry, University of Leeds , Woodhouse Lane, Leeds, LS2 9JT, U.K.|National Centre for Atmospheric Chemistry, University of Leeds , Woodhouse Lane, Leeds, LS2 9JT, U.K.
authors.forename: Dwayne
authors.initials: D
authors.lastname: Heard
authors.affiliation: IMT Lille Douai, Université Lille, SAGE - Département Sciences de l'Atmosphère et Génie de l'Environnement, 59000 Lille, France.
authors.forename: Alexandre
authors.identifier: 0000-0002-0125-581X
authors.initials: A
authors.lastname: Tomas
authors.affiliation: Université Lille, CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France.
authors.forename: Coralie
authors.initials: C
authors.lastname: Schoemaecker
authors.affiliation: Université Lille, CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France.
authors.forename: Christa
authors.identifier: 0000-0003-0932-432X
authors.initials: C
authors.lastname: Fittschen
mesh_terms: D001267:Atlantic Ocean; D001272:Atmosphere / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D000432:Methanol; D008962:Models, Theoretical
chemical_list: D017665:Hydroxyl Radical; D000432:Methanol