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

Secondary Organic Aerosol Reduced by Mixture of Atmospheric Vapours

Thomas Mentel1, Gordon McFiggans2, Jürgen Wildt1, Astrid Kiendler-Scharr1,4, and the JPAC-Team 2015*
Thomas Mentel et al.
  • 1Institut für Energie- und Klimaforschung, IEK-8, Forschungszentrum Jülich, 52425 Jülich, Germany
  • 2University of Manchester, School of Earth and Environmental Sciences, Manchester, M13 9PL, UK
  • 4I. Physikalisches Institut, Universität zu Köln, 50937 Köln, Germany
  • *A full list of authors appears at the end of the abstract

Biogenic volatile organic compounds (VOC) are important secondary organic aerosol (SOA) precursors. Whilst isoprene dominates VOC plant emissions globally, its yield of SOA mass is found to be modest in comparison to that of monoterpenes (MT). Tracers from isoprene oxidation have been observed in particles showing that they condense from the gas phase and yet new particle formation is suppressed by the presence of isoprene in mixtures of plant emissions containing MT.

Experiments were performed in the JPAC chamber in Jülich. We showed that isoprene can suppress both the instantaneous mass formation and overall yield of monoterpenes in mixtures by two effects: oxidant and product scavenging. Isoprene scavenged OH radicals from reacting with MT (oxidant scavenging). Subsequently, the resulting isoprene peroxy radicals reacted with highly oxygenated peroxy radicals from MT oxidation (product scavenging). These effects from isoprene, also demonstrated using CO or CH4, reduced the yield of low-volatility, highly oxygenated molecules (HOM) from MT that would otherwise form SOA.

Our results show that in mixtures changes in particle mass and number are not additive, and yields from single precursor experiments cannot simply be linearly combined. Reactive, modest SOA yield compounds are not necessarily net SOA producers and isoprene oxidation can suppress both SOA number and mass. Global model calculations support that OH scavenging and product scavenging can also operate in the real atmosphere. Our results highlight a need for more realistic consideration of SOA formation in the atmosphere analogous to the treatment of ozone formation, where interactions between the mechanistic pathways involving peroxy radicals are recognised to be essential.

JPAC-Team 2015:

Iida Pullinen1,15, Sungah Kang1, Einhard Kleist3, Sebastian Schmitt1,16, Monika Springer1, Ralf Tillmann1, Cheng Wu1,17, Defeng Zhao5,1, Mattias Hallquist6, Cameron Faxon6, Michael Le Breton1,6, Åsa M. Hallquist7, David Simpson8,12, Robert Bergström6,8,13, Michael E. Jenkin9, Mikael Ehn10, Joel A. Thornton11, M. Rami Alfarra2,14, Thomas J. Bannan2, Carl J. Percival2,18, Michael Priestley2,6, David Topping2,14 1University of Manchester, School of Earth and Environmental Sciences, Manchester, M13 9PL, UK 2Institut für Energie- und Klimaforschung, IEK-8, Forschungszentrum Jülich, 52425 Jülich, Germany 3Institut for Bio- and Geosciences, IBG-2, Forschungszentrum Jülich, Jülich 52425, Germany 5Dept. of Atmospheric and Oceanic Sci. & Institute of Atmospheric Sci., Fudan University, Shanghai, China 6Atmos. Sci., Dept. of Chem. and Molecular Biol., University of Gothenburg, SE-41296 Gothenburg, Sweden 7 IVL Swedish Environmental Research Institute, SE-400 14 Gothenburg, Sweden 8Department of Earth, Space and Environment, Chalmers University of Technology, 41296 Gothenburg, Sweden 9Atmospheric Chemistry Services, Okehampton, Devon, EX20 4QB, UK 10 Inst. for Atmos. and Earth System Res. / Physics, Faculty of Sci., Univ. of Helsinki, 00014, Helsinki, Finland 11Dept. of Atmos. Sciences, University of Washington, Seattle, WA98195, USA 12EMEP MSC-W, Norwegian Meteorological Institute, Oslo, Norway 13Swedish Meteorological and Hydrological Institute, 60176 Norrköping, Sweden 14National Centre for Atmospheric Science (NCAS), Oxford Road, Manchester, M13 9PL, UK 15Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland 16TSI GmbH, 52068 Aachen, Germany 17Stockholm University, Dept. of Environ. Science & Analytic Chemistry, SE-10691 Stockholm, Sweden 18Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA

How to cite: Mentel, T., McFiggans, G., Wildt, J., and Kiendler-Scharr, A. and the JPAC-Team 2015: Secondary Organic Aerosol Reduced by Mixture of Atmospheric Vapours, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8607,, 2020


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