Observational evidence for Criegee intermediate oligomerization reactions relevant to aerosol formation in the troposphere

R. L. Caravan*, T. J. Bannan, F.A.F. Winiberg, M.A.H. Khan, A. C. Rousso, A. W. Jasper, S. D. Worrall, A. Bacak, P. Artaxo, J. Brito, M. Priestley, J. D. Allan, H. Coe, Y. Ju, D. L. Osborn, N. Hansen, S. J. Klippenstein, D. E. Shallcross, C. A. Taatjes, C. J. Percival*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Criegee intermediates are reactive intermediates that are implicated in transforming the composition of Earth’s troposphere and in the formation of secondary organic aerosol, impacting Earth’s radiation balance, air quality and human health. Yet, direct identification of their signatures in the field remains elusive. Here, from particulate and gas-phase mass-spectrometric measurements in the Amazon rainforest, we identify sequences of masses consistent with the expected signatures of oligomerization of the CH2OO Criegee intermediate, a process implicated in ozonolysis-driven aerosol formation. We assess the potential contributions of oligomerization through laboratory ozonolysis experiments, direct kinetic studies of Criegee intermediate reactions, and high-level theoretical calculations. Global atmospheric models built on these kinetics results indicate that Criegee intermediate chemistry may play a larger role in altering the composition of Earth’s troposphere than is captured in current atmospheric models, especially in areas of high humidity. However, the models still capture only a relatively small fraction of the observed signatures, suggesting considerable underestimates of Criegee intermediate concentrations and reactivity and/or the dominance of other, presently uncharacterized, oxidation mechanisms. Resolving the remaining uncertainties in emission inventories and the effects of atmospheric water vapour on key chemical reactions will be required to definitively assess the role of Criegee intermediate oligomerization reactions.

Original languageEnglish
Pages (from-to)219-226
Number of pages8
JournalNature Geoscience
Issue number3
Early online date5 Mar 2024
Publication statusPublished - 5 Mar 2024

Bibliographical note

Copyright © UChicago Argonne, LLC Operator of Argonne National Laboratory and NASA Jet Propulsion Laboratory, under exclusive licence to Springer Nature Limited, 2024. This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use [https://www.springernature.com/gp/open-research/policies/accepted-manuscript-terms], but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1038/s41561-023-01361-6

Data Access Statement

The data supporting the findings of this study are shown as figures or tables available in the main text or Supplementary Information, and are available alongside the master equation input and output files at https://doi.org/10.5281/zenodo.10267863.

The codes used for the theoretical kinetics work are available at https://tcg.cse.anl.gov/papr/, https://github.com/auto-mech, https://comp.chem.umn.edu/dint/ and https://github.com/Auto-Mech/PIPPy, or are commercially available. The codes used for the atmospheric modelling work are available at https://github.com/chmahk/stochem.


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