Articles | Volume 17, issue 12
Atmos. Chem. Phys., 17, 7807–7826, 2017
Atmos. Chem. Phys., 17, 7807–7826, 2017

Research article 29 Jun 2017

Research article | 29 Jun 2017

Estimating the atmospheric concentration of Criegee intermediates and their possible interference in a FAGE-LIF instrument

Anna Novelli1,a, Korbinian Hens1, Cheryl Tatum Ernest1,b, Monica Martinez1, Anke C. Nölscher1,c, Vinayak Sinha2, Pauli Paasonen3, Tuukka Petäjä3, Mikko Sipilä3, Thomas Elste4, Christian Plass-Dülmer4, Gavin J. Phillips1,5, Dagmar Kubistin1,4,6, Jonathan Williams1, Luc Vereecken1,a, Jos Lelieveld1, and Hartwig Harder1 Anna Novelli et al.
  • 1Atmospheric Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
  • 2Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81 S.A.S. Nagar, Manauli PO, Mohali 140 306, Punjab, India
  • 3Department of Physics., P.O. Box 64. 00014 University of Helsinki, Helsinki, Finland
  • 4German Meteorological Service, Meteorological Observatory Hohenpeissenberg (MOHp), 83282 Hohenpeissenberg, Germany
  • 5Department of Natural Sciences, University of Chester, Thornton Science Park, Chester, CH2 4NU, UK
  • 6University of Wollongong, School of Chemistry, Wollongong, Australia
  • anow at: Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
  • bnow at: Department of Neurology University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
  • cnow at: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, USA

Abstract. We analysed the extensive dataset from the HUMPPA-COPEC 2010 and the HOPE 2012 field campaigns in the boreal forest and rural environments of Finland and Germany, respectively, and estimated the abundance of stabilised Criegee intermediates (SCIs) in the lower troposphere. Based on laboratory tests, we propose that the background OH signal observed in our IPI-LIF-FAGE instrument during the aforementioned campaigns is caused at least partially by SCIs. This hypothesis is based on observed correlations with temperature and with concentrations of unsaturated volatile organic compounds and ozone. Just like SCIs, the background OH concentration can be removed through the addition of sulfur dioxide. SCIs also add to the previously underestimated production rate of sulfuric acid. An average estimate of the SCI concentration of  ∼  5.0  ×  104 molecules cm−3 (with an order of magnitude uncertainty) is calculated for the two environments. This implies a very low ambient concentration of SCIs, though, over the boreal forest, significant for the conversion of SO2 into H2SO4. The large uncertainties in these calculations, owing to the many unknowns in the chemistry of Criegee intermediates, emphasise the need to better understand these processes and their potential effect on the self-cleaning capacity of the atmosphere.

Short summary
The ambient concentration of stabilised Criegee intermediates (SCIs) was estimated for two environments using field data. The low concentrations predicted indicate that SCIs are unlikely to have a large impact on atmospheric chemistry. Concurrent measurements of an OH background signal using the Mainz IPI-LIF-FAGE instrument were found to be consistent with the chemistry of SCIs during the measurement campaigns.
Final-revised paper