Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 15, 10701-10721, 2015
© Author(s) 2015. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
25 Sep 2015
Thermodynamics of the formation of sulfuric acid dimers in the binary (H2SO4–H2O) and ternary (H2SO4–H2O–NH3) system
A. Kürten1, S. Münch1, L. Rondo1, F. Bianchi2,3, J. Duplissy4,a, T. Jokinen5, H. Junninen5, N. Sarnela5, S. Schobesberger5,b, M. Simon1, M. Sipilä5, J. Almeida4, A. Amorim6, J. Dommen2, N. M. Donahue7, E. M. Dunne8,c, R. C. Flagan9, A. Franchin5, J. Kirkby1,4, A. Kupc10, V. Makhmutov11, T. Petäjä5, A. P. Praplan2,5,d, F. Riccobono2,e, G. Steiner5,12,f, A. Tomé6, G. Tsagkogeorgas13, P. E. Wagner10, D. Wimmer1,a, U. Baltensperger2, M. Kulmala5, D. R. Worsnop5,14, and J. Curtius1 1Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
2Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Switzerland
3Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
4CERN (European Organization for Nuclear Research), Geneva, Switzerland
5Department of Physics, University of Helsinki, Helsinki, Finland
6Laboratory for Systems, Instrumentation, and Modeling in Science and Technology for Space and the Environment (SIM), University of Lisbon and University of Beira Interior, Lisbon, Portugal
7Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, USA
8School of Earth and Environment, University of Leeds, Leeds, UK
9Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, USA
10Aerosol Physics and Environmental Physics, University of Vienna, Vienna, Austria
11Solar and Cosmic Ray Research Laboratory, Lebedev Physical Institute, Moscow, Russia
12Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria
13Leibniz Institute for Tropospheric Research, Leipzig, Germany
14Aerodyne Research Incorporated, Billerica, MA, USA
anow at: Helsinki Institute of Physics, University of Helsinki, Helsinki, Finland
bnow at: Department of Atmospheric Sciences, University of Washington, Seattle, USA
cnow at: Finnish Meteorological Institute, Kuopio, Finland
dnow at: Finnish Meteorological Institute, Helsinki, Finland
enow at: Joint Research Centre, European Commission, Ispra, Italy
fnow at: Faculty of Physics, University of Vienna, Vienna, Austria
Abstract. Sulfuric acid is an important gas influencing atmospheric new particle formation (NPF). Both the binary (H2SO4–H2O) system and the ternary system involving ammonia (H2SO4–H2O–NH3) may be important in the free troposphere. An essential step in the nucleation of aerosol particles from gas-phase precursors is the formation of a dimer, so an understanding of the thermodynamics of dimer formation over a wide range of atmospheric conditions is essential to describe NPF. We have used the CLOUD chamber to conduct nucleation experiments for these systems at temperatures from 208 to 248 K. Neutral monomer and dimer concentrations of sulfuric acid were measured using a chemical ionization mass spectrometer (CIMS). From these measurements, dimer evaporation rates in the binary system were derived for temperatures of 208 and 223 K. We compare these results to literature data from a previous study that was conducted at higher temperatures but is in good agreement with the present study. For the ternary system the formation of H2SO4·NH3 is very likely an essential step in the formation of sulfuric acid dimers, which were measured at 210, 223, and 248 K. We estimate the thermodynamic properties (dH and dS) of the H2SO4·NH3 cluster using a simple heuristic model and the measured data. Furthermore, we report the first measurements of large neutral sulfuric acid clusters containing as many as 10 sulfuric acid molecules for the binary system using chemical ionization–atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometry.

Citation: Kürten, A., Münch, S., Rondo, L., Bianchi, F., Duplissy, J., Jokinen, T., Junninen, H., Sarnela, N., Schobesberger, S., Simon, M., Sipilä, M., Almeida, J., Amorim, A., Dommen, J., Donahue, N. M., Dunne, E. M., Flagan, R. C., Franchin, A., Kirkby, J., Kupc, A., Makhmutov, V., Petäjä, T., Praplan, A. P., Riccobono, F., Steiner, G., Tomé, A., Tsagkogeorgas, G., Wagner, P. E., Wimmer, D., Baltensperger, U., Kulmala, M., Worsnop, D. R., and Curtius, J.: Thermodynamics of the formation of sulfuric acid dimers in the binary (H2SO4–H2O) and ternary (H2SO4–H2O–NH3) system, Atmos. Chem. Phys., 15, 10701-10721, doi:10.5194/acp-15-10701-2015, 2015.
Publications Copernicus
Short summary
New particle formation (NPF) is an important atmospheric process. At cold temperatures in the upper troposphere the binary (H2SO4-H2O) and ternary (H2SO4-H2O-NH3) system are thought to be important for NPF. Sulfuric acid monomer (H2SO4) and sulfuric acid dimer ((H2SO4)2) concentrations were measured between 208 and 248K for these systems and dimer evaporation rates were derived. These data will help to better understand and predict binary and ternary nucleation at low temperatures.
New particle formation (NPF) is an important atmospheric process. At cold temperatures in the...