Articles | Volume 11, issue 15
Atmos. Chem. Phys., 11, 7839–7858, 2011
Atmos. Chem. Phys., 11, 7839–7858, 2011

Research article 03 Aug 2011

Research article | 03 Aug 2011

Surface modification of mineral dust particles by sulphuric acid processing: implications for ice nucleation abilities

P. Reitz1,2, C. Spindler3, T. F. Mentel3, L. Poulain4, H. Wex4, K. Mildenberger4, D. Niedermeier4, S. Hartmann4, T. Clauss4, F. Stratmann4, R. C. Sullivan5, P. J. DeMott5, M. D. Petters6, B. Sierau7, and J. Schneider1 P. Reitz et al.
  • 1Particle Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
  • 2Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
  • 3Institute for Energy- and Climate Research Troposphere (IEK-8), Research Center Jülich GmbH, Jülich, Germany
  • 4Department of Physics, Leibniz Institute for Tropospheric Research, Leipzig, Germany
  • 5Department of Atmospheric Science, Colorado State University, Fort Collins, USA
  • 6Department of Marine Earth and Atmospheric Science, North Carolina State University, Raleigh, USA
  • 7Institute for Atmospheric and Climate Science, ETH Zürich, Zürich, Switzerland

Abstract. The ability of coated mineral dust particles to act as ice nuclei (IN) was investigated at LACIS (Leipzig Aerosol Cloud Interaction Simulator) during the FROST1- and FROST2-campaigns (Freezing of dust). Sulphuric acid was condensed on the particles which afterwards were optionally humidified, treated with ammonia vapour and/or heat. By means of aerosol mass spectrometry we found evidence that processing of mineral dust particles with sulphuric acid leads to surface modifications of the particles. These surface modifications are most likely responsible for the observed reduction of the IN activation of the particles. The observed particle mass spectra suggest that different treatments lead to different chemical reactions on the particle surface. Possible chemical reaction pathways and products are suggested and the implications on the IN efficiency of the treated dust particles are discussed.

Final-revised paper