title: Temperature dependence of the rate coefficient for the alpha-pinene reaction with ozone in the range between 243 K and 303 K.
abstract: The absolute rate coefficient for the reaction of alpha-pinene with ozone was determined in the temperature range between 243 K and 303 K at atmospheric pressure. In total, 30 experiments were performed in the large (85 m3) temperature-controlled simulation chamber AIDA, where the concentrations of the reactants ozone and alpha-pinene were measured directly. An Arrhenius expression for the alpha-pinene + ozone reaction was derived with a pre-exponential factor of (1.4 +/- 0.4) x 10(-15) cm3 s(-1) and a temperature coefficient of (833 +/- 86) K. This rate coefficient is in good agreement (-5%) with the current IUPAC (IUPAC 2007) recommendation at 298 K. The IUPAC recommendation is significantly larger (+27%), around 243 K where the recommended values were extrapolated from higher temperatures. This finding is relevant for tropical regions where strong updrafts can rapidly transport reactive hydrocarbons like alpha-pinene from the boundary layer into the cold regions of the free troposphere.
authors.affiliation: Institut für Chemie und Dynamik der Geosphäre 2: Troposphäre, Forschungszentrum Jülich, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Tillmann
authors.forename: Harald
authors.initials: H
authors.lastname: Saathoff
authors.forename: Theo
authors.initials: T
authors.lastname: Brauers
authors.forename: Astrid
authors.initials: A
authors.lastname: Kiendler-Scharr
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Mentel
mesh_terms: D000042:Absorption; D000081008:Bicyclic Monoterpenes; D007700:Kinetics; D013058:Mass Spectrometry; D039821:Monoterpenes / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D011522:Protons; D013696:Temperature; D014329:Tropical Climate; D014466:Ultraviolet Rays
chemical_list: D000081008:Bicyclic Monoterpenes; D039821:Monoterpenes; D011522:Protons; D010126:Ozone; C005451:alpha-pinene