Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 1747-1760, 2016
https://doi.org/10.5194/acp-16-1747-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
15 Feb 2016
Secondary organic aerosol formation from isoprene photooxidation during cloud condensation–evaporation cycles
L. Brégonzio-Rozier1, C. Giorio2,3, F. Siekmann4, E. Pangui1, S. B. Morales1, B. Temime-Roussel4, A. Gratien1, V. Michoud1, M. Cazaunau1, H. L. DeWitt4, A. Tapparo3, A. Monod4, and J.-F. Doussin1 1Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR7583, CNRS, Université Paris-Est-Créteil (UPEC) et Université Paris Diderot (UPD), Institut Pierre Simon Laplace (IPSL), Créteil, France
2Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
3Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Padova, 35131, Italy
4Aix-Marseille Université, CNRS, LCE FRE 3416, 13331, Marseille, France
Abstract. The impact of cloud events on isoprene secondary organic aerosol (SOA) formation has been studied from an isoprene ∕ NOx ∕ light system in an atmospheric simulation chamber. It was shown that the presence of a liquid water cloud leads to a faster and higher SOA formation than under dry conditions. When a cloud is generated early in the photooxidation reaction, before any SOA formation has occurred, a fast SOA formation is observed with mass yields ranging from 0.002 to 0.004. These yields are 2 and 4 times higher than those observed under dry conditions. When the cloud is generated at a later photooxidation stage, after isoprene SOA is stabilized at its maximum mass concentration, a rapid increase (by a factor of 2 or higher) of the SOA mass concentration is observed. The SOA chemical composition is influenced by cloud generation: the additional SOA formed during cloud events is composed of both organics and nitrate containing species. This SOA formation can be linked to the dissolution of water soluble volatile organic compounds (VOCs) in the aqueous phase and to further aqueous phase reactions. Cloud-induced SOA formation is experimentally demonstrated in this study, thus highlighting the importance of aqueous multiphase systems in atmospheric SOA formation estimations.

Citation: Brégonzio-Rozier, L., Giorio, C., Siekmann, F., Pangui, E., Morales, S. B., Temime-Roussel, B., Gratien, A., Michoud, V., Cazaunau, M., DeWitt, H. L., Tapparo, A., Monod, A., and Doussin, J.-F.: Secondary organic aerosol formation from isoprene photooxidation during cloud condensation–evaporation cycles, Atmos. Chem. Phys., 16, 1747-1760, https://doi.org/10.5194/acp-16-1747-2016, 2016.
Publications Copernicus
Download
Short summary
The impact of cloud events on isoprene secondary organic aerosol (SOA) formation has been studied from an isoprene/ NOx/light system in an atmospheric simulation chamber. aqSOA formation can be linked to water soluble volatile organic compounds' dissolution in the aqueous phase and to further aqueous phase reactions. Cloud-induced SOA formation is experimentally demonstrated in this study, thus highlighting the importance of aqueous multiphase systems in atmospheric SOA formation estimations.
The impact of cloud events on isoprene secondary organic aerosol (SOA) formation has been...
Share