CaltechAUTHORS
Published November 25, 2021 | Version Published + Supplemental Material
Journal Article Open

Chemical composition of nanoparticles from α-pinene nucleation and the influence of isoprene and relative humidity at low temperature

Creators

  • 1. ROR icon Goethe University Frankfurt
  • 2. ROR icon University of Helsinki
  • 3. ROR icon University of Colorado Boulder
  • 4. ROR icon Max Planck Institute for Chemistry
  • 5. ROR icon University of Lisbon
  • 6. ROR icon Leibniz Institute for Tropospheric Research
  • 7. ROR icon Karlsruhe Institute of Technology
  • 8. ROR icon Paul Scherrer Institute
  • 9. ROR icon University of Vienna
  • 10. ROR icon Carnegie Mellon University
  • 11. ROR icon California Institute of Technology
  • 12. ROR icon California Air Resources Board
  • 13. ROR icon P.N. Lebedev Physical Institute of the Russian Academy of Sciences
  • 14. ROR icon Moscow Power Engineering Institute
  • 15. ROR icon European Organization for Nuclear Research
  • 16. ROR icon Universität Innsbruck
  • 17. ROR icon Swiss Federal Institute for Forest, Snow and Landscape Research
  • 18. ROR icon University of California, Irvine
  • 19. ROR icon Finnish Meteorological Institute
  • 20. ROR icon Beijing Meteorological Bureau
  • 21. ROR icon University of Beira Interior
  • 22. ROR icon Ionicon Analytik (Austria)
  • 23. ROR icon Beijing University of Chemical Technology

Abstract

Biogenic organic precursors play an important role in atmospheric new particle formation (NPF). One of the major precursor species is α-pinene, which upon oxidation can form a suite of products covering a wide range of volatilities. Highly oxygenated organic molecules (HOMs) comprise a fraction of the oxidation products formed. While it is known that HOMs contribute to secondary organic aerosol (SOA) formation, including NPF, they have not been well studied in newly formed particles due to their very low mass concentrations. Here we present gas- and particle-phase chemical composition data from experimental studies of α-pinene oxidation, including in the presence of isoprene, at temperatures (−50 and −30 ∘C) and relative humidities (20 % and 60 %) relevant in the upper free troposphere. The measurements took place at the CERN Cosmics Leaving Outdoor Droplets (CLOUD) chamber. The particle chemical composition was analyzed by a thermal desorption differential mobility analyzer (TD-DMA) coupled to a nitrate chemical ionization–atmospheric pressure interface–time-of-flight (CI-APi-TOF) mass spectrometer. CI-APi-TOF was used for particle- and gas-phase measurements, applying the same ionization and detection scheme. Our measurements revealed the presence of C₈₋₁₀ monomers and C₁₈₋₂₀ dimers as the major compounds in the particles (diameter up to ∼ 100 nm). Particularly, for the system with isoprene added, C₅ (C₅H₁₀O₅₋₇) and C₁₅ compounds (C₁₅H₂₄O₅₋₁₀) were detected. This observation is consistent with the previously observed formation of such compounds in the gas phase. However, although the C₅ and C₁₅ compounds do not easily nucleate, our measurements indicate that they can still contribute to the particle growth at free tropospheric conditions. For the experiments reported here, most likely isoprene oxidation products enhance the growth of particles larger than 15 nm. Additionally, we report on the nucleation rates measured at 1.7 nm (J_(1.7 nm)) and compared with previous studies, we found lower J_(1.7 nm) values, very likely due to the higher α-pinene and ozone mixing ratios used in the present study.

Additional Information

© Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Received: 16 Jun 2021 – Discussion started: 07 Jul 2021 – Revised: 15 Oct 2021 – Accepted: 17 Oct 2021 – Published: 25 Nov 2021. We thank CERN for providing the CLOUD facility to perform the experiments and the CLOUD community for supporting this study. We especially would like to thank Katja Ivanova, Timo Keber, Frank Malkemper, Robert Sitals, Hanna Elina Manninen, Antti Onnela, and Robert Kristic for their contributions to the experiment. This research has been supported by the European Commission, Research Executive Agency (grant no. CLOUD-MOTION (764991)), the Bundesministerium für Bildung und Forschung (grant no. CLOUD-16, 01LK1601A), the National Science Foundation (grant nos. AGS-1801280, AGS-1801574, and AGS-1801897), and the Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (grant nos. 20020_172602 and BSSGI0_155846). This open-access publication was funded by the Goethe University Frankfurt. Data availability. Data related to this article are available upon request to the corresponding authors. The supplement related to this article is available online at: https://doi.org/10.5194/acp-21-17099-2021-supplement. The contact author has declared that neither they nor their co-authors have any competing interests. The contact author has declared that neither they nor their co-authors have any competing interests.

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Published - acp-21-17099-2021.pdf

Supplemental Material - acp-21-17099-2021-supplement.pdf

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Additional details

Identifiers

Eprint ID
112440
Resolver ID
CaltechAUTHORS:20211214-82816000

Funding

Marie Curie Fellowship
764991
Bundesministerium für Bildung und Forschung (BMBF)
CLOUD-16, 01LK1601A
NSF
AGS-1801280
NSF
AGS-1801574
NSF
AGS-1801897
Swiss National Science Foundation (SNSF)
20020_172602
Swiss National Science Foundation (SNSF)
BSSGI0_155846

Dates

Created
2021-12-15
Created from EPrint's datestamp field
Updated
2022-02-01
Created from EPrint's last_modified field