EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

New insights into the gas-phase oxidation of isoprene by the nitrate radical from experiments in the atmospheric simulation chamber SAPHIR

Philip Carlsson1, Patrick Dewald2, Justin Shenolikar2, Nils Friedrich2, John Crowley2, Steven Brown3, François Bernard4, Li Zhou4, Juliane Fry5, Bellamy Brownwood5, Mattias Hallquist6, Epameinondas Tsiligiannis6, Xu Kangmin7, Rupert Holzinger7, Hendrik Fuchs1, Luc Vereecken1, Anna Novelli1, Birger Bohn1, Franz Rohrer1, Thomas Mentel1, and the NO3-Isoprene Campaign at Saphir*
Philip Carlsson et al.
  • 1IEK 8, Forschungszentrum Jülich GmbH, Jülich, Germany
  • 2Max-Planck Institute for Chemistry, Mainz, Germany
  • 3NOAA Earth System Research Laboratory, Boulder, CO, United States
  • 4CNRS, Orleans, France
  • 5Reed College, Chemistry and Environmental Studies, Portland, United States
  • 6University of Gothenburg, Department of Chemistry, Atmoshperic Sciences, Gothenburg, Sweden
  • 7Institute for Marine and Atmospheric Research Utrecht, Utrecht, Netherlands
  • *A full list of authors appears at the end of the abstract

Experiments at a set of atmospherically relevant conditions were performed in the simulation chamber SAPHIR, investigating the oxidation of isoprene by the nitrate radical (NO3). An extremely comprehensive set of instruments detected trace gases, radicals, aerosol properties and hydroxyl (OH) and NO3 radical reactivity. The chemical conditions in the chamber were varied to change the fate of the peroxy radicals (RO2) formed after the reaction between NO3 and isoprene from either mainly recombining with other RO2 or mainly reacting with hydroperoxyl radicals (HO2). These major atmospheric pathways for RO2 radicals lead to the formation of organic nitrate compounds which then have different atmospheric fates. The experimental concentration profiles are compared to box model calculations using both the current Master Chemical Mechanism (MCM) as well as recently available literature data alongside new quantum chemical calculations. The discussion here focusses on the resulting RO2 distribution and deviations in the predictions of early products and total alkyl nitrate yields for the different chemical conditions. Preliminary results for instance show too high night time losses of alkyl nitrates due to ozonolysis in the current MCM. 

NO3-Isoprene Campaign at Saphir:

Changmin Cho, Peter Edwards, Luisa Hantschke, Sungah Kang, David Reimer, Ralf Tillmann, Sergej Wedel, Rongrong Wu

How to cite: Carlsson, P., Dewald, P., Shenolikar, J., Friedrich, N., Crowley, J., Brown, S., Bernard, F., Zhou, L., Fry, J., Brownwood, B., Hallquist, M., Tsiligiannis, E., Kangmin, X., Holzinger, R., Fuchs, H., Vereecken, L., Novelli, A., Bohn, B., Rohrer, F., and Mentel, T. and the NO3-Isoprene Campaign at Saphir: New insights into the gas-phase oxidation of isoprene by the nitrate radical from experiments in the atmospheric simulation chamber SAPHIR, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11196,, 2020

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