Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.414 IF 5.414
  • IF 5-year value: 5.958 IF 5-year
  • CiteScore value: 9.7 CiteScore
  • SNIP value: 1.517 SNIP 1.517
  • IPP value: 5.61 IPP 5.61
  • SJR value: 2.601 SJR 2.601
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 191 Scimago H
    index 191
  • h5-index value: 89 h5-index 89
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  10 Feb 2020

10 Feb 2020

Review status
This preprint is currently under review for the journal ACP.

The Aarhus Chamber Campaign on Highly Oxidized Multifunctional Organic Molecules and Aerosols (ACCHA): Particle Formation and Detailed Chemical Composition at Different Temperatures

Kasper Kristensen1, Louise N. Jensen2, Lauriane L. J. Quéléver3, Sigurd Christiansen2, Bernadette Rosati2,4, Jonas Elm2, Ricky Teiwes4, Henrik B. Pedersen4, Marianne Glasius2, Mikael Ehn3, and Merete Bilde2 Kasper Kristensen et al.
  • 1Department of Engineering, Aarhus University, 8000 Aarhus C, Denmark
  • 2Department of Chemistry and iClimate, Aarhus University, 8000 Aarhus C, Denmark
  • 3Institute for Atmospheric and Earth System Research – INAR/Physics, P.O. Box 64, 00014, University of Helsinki, Finland
  • 4Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark

Abstract. Little is known about the effects of low temperatures on the formation of SOA from α-pinene. In the current work, ozone-initiated oxidation of α-pinene at initial concentrations of 10 and 50 ppb, respectively, is performed at temperatures of 20, 0 and −15 °C in the Aarhus University Research on Aerosol (AURA) smog chamber during the Aarhus Chamber Campaign on highly oxidized multifunctional organic molecules and Aerosol (ACCHA). Here, we show how temperature influences the formation and chemical composition of α-pinene-derived SOA with a specific focus on the formation of organic acids and dimer esters. With respect to particle formation, results show significant increase in both particle formation rates, particle number concentrations and particle mass concentrations at lower temperatures. In particular, the number concentrations of sub-10 nm particles were significantly enhanced at the lower 0 and -15 °C temperatures. Temperatures also affect chemical composition of the formed SOA. Here, detailed off-line chemical analyses show organic acids contributing from 15 to 30 % by mass, with highest contributions observed at the lower temperatures indicative of enhanced condensation of these semi-volatile species. In comparison, 30 identified dimer esters contribute between 4–11 % to SOA mass. No significant differences in the chemical composition (i.e. organic acids and dimer esters) of the α-pinene-derived SOA particles are observed between experiments performed at 10 and 50 ppb initial α-pinene concentrations, thus suggesting a higher influence of reaction temperature compared to that of α-pinene loading on the SOA chemical composition. Interestingly, the effect of temperature on the formation of dimer esters differs between the individual species. The formation of less oxidized (oxygen-to-carbon ratio (O:C) < 0.4) dimer esters is shown to increase at lower temperatures while the formation of the more oxidized (O:C > 0.4) species is suppressed, consequently resulting in temperature-modulated composition of the α-pinene derived SOA. Temperature ramping experiments exposing α-pinene-derived SOA to changing temperatures (heating and cooling) reveal that the chemical composition of the SOA with respect to dimer esters is governed almost solely by the temperature during the initial oxidization and insusceptible to subsequent changes in temperature. Similarly, the resulting SOA mass concentrations were found to be more influenced by the initial α-pinene oxidation temperatures, thus suggesting that the formation conditions to a large extent govern the type of SOA formed, rather than the conditions to which the SOA is later exposed.

For the first time, we discuss the relation between the identified dimer ester and the highly oxidized multifunctional organic molecules (HOMs) measured by Chemical Ionization Atmospheric Pressure interface Time-of-Flight mass spectrometer (CI-APi-TOF) during ACCHA experiments. We propose that, although very different in chemical structures and O:C-ratios, dimer esters and HOMs may be linked through the mechanism of RO2 autoxidation, and that dimer esters and HOMs merely represent two different fates of the RO2 radicals.

Kasper Kristensen et al.

Interactive discussion

Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Kasper Kristensen et al.

Kasper Kristensen et al.


Total article views: 463 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
320 129 14 463 39 10 10
  • HTML: 320
  • PDF: 129
  • XML: 14
  • Total: 463
  • Supplement: 39
  • BibTeX: 10
  • EndNote: 10
Views and downloads (calculated since 10 Feb 2020)
Cumulative views and downloads (calculated since 10 Feb 2020)

Viewed (geographical distribution)

Total article views: 443 (including HTML, PDF, and XML) Thereof 441 with geography defined and 2 with unknown origin.
Country # Views %
  • 1



No saved metrics found.


No discussed metrics found.
Latest update: 07 Aug 2020
Publications Copernicus
Short summary
Atmospheric particles are important in relation to human health and the global climate. As the global temperature changes, so may the atmospheric chemistry controlling the formation of particles formed from the reactions of natural emitted volatile organic compounds (VOCs). In the current work, we show how temperatures influence the formation and chemical composition of atmospheric particles from α-pinene; a biogenic VOC largely emitted in high-latitude environments such as the boreal forests.
Atmospheric particles are important in relation to human health and the global climate. As the...