Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 18, 65-79, 2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
04 Jan 2018
Influence of temperature on the molecular composition of ions and charged clusters during pure biogenic nucleation
Carla Frege1, Ismael K. Ortega2, Matti P. Rissanen3, Arnaud P. Praplan3, Gerhard Steiner3,4,5, Martin Heinritzi6, Lauri Ahonen3, António Amorim7, Anne-Kathrin Bernhammer4,18, Federico Bianchi1,3, Sophia Brilke4,5,6, Martin Breitenlechner4,a, Lubna Dada3, António Dias7, Jonathan Duplissy3,8, Sebastian Ehrhart8,b, Imad El-Haddad1, Lukas Fischer4, Claudia Fuchs1, Olga Garmash3, Marc Gonin9, Armin Hansel4,18, Christopher R. Hoyle1, Tuija Jokinen3, Heikki Junninen3,17, Jasper Kirkby6,8, Andreas Kürten6, Katrianne Lehtipalo1,3, Markus Leiminger4,6, Roy Lee Mauldin3,16, Ugo Molteni1, Leonid Nichman10, Tuukka Petäjä3, Nina Sarnela3, Siegfried Schobesberger3,14, Mario Simon6, Mikko Sipilä3, Dominik Stolzenburg5, António Tomé11, Alexander L. Vogel1,8, Andrea C. Wagner6, Robert Wagner3, Mao Xiao1, Chao Yan3, Penglin Ye12,15, Joachim Curtius4, Neil M. Donahue12, Richard C. Flagan13, Markku Kulmala3, Douglas R. Worsnop3,14,15, Paul M. Winkler5, Josef Dommen1, and Urs Baltensperger1 1Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, 5232 Villigen, Switzerland
2ONERA – The French Aerospace Lab, 91123 Palaiseau, France
3University of Helsinki, Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland
4University of Innsbruck, Institute of Ion Physics and Applied Physics, Technikerstraße 25, 6020 Innsbruck, Austria
5University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna, Austria
6Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
7Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisbon, Portugal
8CERN, Geneva, Switzerland
9Tofwerk AG, 3600 Thun, Switzerland
10School of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9PL, UK
11IDL – Universidade da Beira Interior, Av. Marquês D'Avila e Bolama, 6201-001 Covilhã, Portugal
12Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, Pennsylvania, 15213, USA
13Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, 91125, USA
14University of Eastern Finland, Department of Applied Physics, 70211 Kuopio, Finland
15Aerodyne Research Inc., Billerica, Massachusetts, 01821, USA
16Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado, 80309-0311, USA
17University of Tartu, Institute of Physics, 50090 Tartu, Estonia
18Ionicon Analytik GmbH, Eduard-Bodem Gasse 3, 6020 Innsbruck, Austria
anow at: Harvard University, School of Engineering and Applied Sciences, Cambridge, MA 02138, USA
bnow at: Max-Planck Institute of Chemistry, Atmospheric Chemistry Department, 55128 Mainz, Germany
Abstract. It was recently shown by the CERN CLOUD experiment that biogenic highly oxygenated molecules (HOMs) form particles under atmospheric conditions in the absence of sulfuric acid, where ions enhance the nucleation rate by 1–2 orders of magnitude. The biogenic HOMs were produced from ozonolysis of α-pinene at 5 °C. Here we extend this study to compare the molecular composition of positive and negative HOM clusters measured with atmospheric pressure interface time-of-flight mass spectrometers (APi-TOFs), at three different temperatures (25, 5 and −25 °C). Most negative HOM clusters include a nitrate (NO3) ion, and the spectra are similar to those seen in the nighttime boreal forest. On the other hand, most positive HOM clusters include an ammonium (NH4+) ion, and the spectra are characterized by mass bands that differ in their molecular weight by ∼ 20 C atoms, corresponding to HOM dimers. At lower temperatures the average oxygen to carbon (O : C) ratio of the HOM clusters decreases for both polarities, reflecting an overall reduction of HOM formation with decreasing temperature. This indicates a decrease in the rate of autoxidation with temperature due to a rather high activation energy as has previously been determined by quantum chemical calculations. Furthermore, at the lowest temperature (−25 °C), the presence of C30 clusters shows that HOM monomers start to contribute to the nucleation of positive clusters. These experimental findings are supported by quantum chemical calculations of the binding energies of representative neutral and charged clusters.

Citation: Frege, C., Ortega, I. K., Rissanen, M. P., Praplan, A. P., Steiner, G., Heinritzi, M., Ahonen, L., Amorim, A., Bernhammer, A.-K., Bianchi, F., Brilke, S., Breitenlechner, M., Dada, L., Dias, A., Duplissy, J., Ehrhart, S., El-Haddad, I., Fischer, L., Fuchs, C., Garmash, O., Gonin, M., Hansel, A., Hoyle, C. R., Jokinen, T., Junninen, H., Kirkby, J., Kürten, A., Lehtipalo, K., Leiminger, M., Mauldin, R. L., Molteni, U., Nichman, L., Petäjä, T., Sarnela, N., Schobesberger, S., Simon, M., Sipilä, M., Stolzenburg, D., Tomé, A., Vogel, A. L., Wagner, A. C., Wagner, R., Xiao, M., Yan, C., Ye, P., Curtius, J., Donahue, N. M., Flagan, R. C., Kulmala, M., Worsnop, D. R., Winkler, P. M., Dommen, J., and Baltensperger, U.: Influence of temperature on the molecular composition of ions and charged clusters during pure biogenic nucleation, Atmos. Chem. Phys., 18, 65-79,, 2018.
Publications Copernicus
Short summary
It was recently shown that biogenic highly oxygenated molecules (HOMs) form particles in the absence of sulfuric acid and ions enhance the nucleation rate. Here we compare the molecular composition of positive and negative HOM clusters at 25, 5 and −25 °C. At lower temperatures the HOM average oxygen-to-carbon ratio decreases indicating a reduction in the rate of autoxidation due to rather high activation energy. The experimental findings are supported by quantum chemical calculations.
It was recently shown that biogenic highly oxygenated molecules (HOMs) form particles in the...