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: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Volume 16, issue 9
Atmos. Chem. Phys., 16, 5531-5543, 2016
https://doi.org/10.5194/acp-16-5531-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Results from the ice nucleation research unit (INUIT) (ACP/AMT...

Atmos. Chem. Phys., 16, 5531-5543, 2016
https://doi.org/10.5194/acp-16-5531-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 04 May 2016

Research article | 04 May 2016

Laboratory-generated mixtures of mineral dust particles with biological substances: characterization of the particle mixing state and immersion freezing behavior

Stefanie Augustin-Bauditz1,*, Heike Wex1, Cyrielle Denjean1,4, Susan Hartmann1, Johannes Schneider2, Susann Schmidt2, Martin Ebert3, and Frank Stratmann1 Stefanie Augustin-Bauditz et al.
  • 1Leibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, Germany
  • 2Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
  • 3Institute of Applied Geosciences, Schnittspahnstraße 9, 64287 Darmstadt, Germany
  • 4National Centre for Meteorological Research, 42 avenue Gaspard Coriolis, 31057 Toulouse, France
  • * Invited contribution by S. Augustin-Bauditz, recipient of the EGU Outstanding Student Poster (OSP) Award 2014.

Abstract. Biological particles such as bacteria, fungal spores or pollen are known to be efficient ice nucleating particles. Their ability to nucleate ice is due to ice nucleation active macromolecules (INMs). It has been suggested that these INMs maintain their nucleating ability even when they are separated from their original carriers. This opens the possibility of an accumulation of such INMs in soils, resulting in an internal mixture of mineral dust and INMs. If particles from such soils which contain biological INMs are then dispersed into the atmosphere due to wind erosion or agricultural processes, they could induce ice nucleation at temperatures typical for biological substances, i.e., above −20 up to almost 0°C, while they might be characterized as mineral dust particles due to a possibly low content of biological material.

We conducted a study within the research unit INUIT (Ice Nucleation research UnIT), where we investigated the ice nucleation behavior of mineral dust particles internally mixed with INM. Specifically, we mixed a pure mineral dust sample (illite-NX) with ice active biological material (birch pollen washing water) and quantified the immersion freezing behavior of the resulting particles utilizing the Leipzig Aerosol Cloud Interaction Simulator (LACIS). A very important topic concerning the investigations presented here as well as for atmospheric application is the characterization of the mixing state of aerosol particles. In the present study we used different methods like single-particle aerosol mass spectrometry, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), and a Volatility–Hygroscopicity Tandem Differential Mobility Analyser (VH-TDMA) to investigate the mixing state of our generated aerosol. Not all applied methods performed similarly well in detecting small amounts of biological material on the mineral dust particles. Measuring the hygroscopicity/volatility of the mixed particles with the VH-TDMA was the most sensitive method. We found that internally mixed particles, containing ice active biological material, follow the ice nucleation behavior observed for the pure biological particles. We verified this by modeling the freezing behavior of the mixed particles with the Soccerball model (SBM). It can be concluded that a single INM located on a mineral dust particle determines the freezing behavior of that particle with the result that freezing occurs at temperatures at which pure mineral dust particles are not yet ice active.

Publications Copernicus
Special issue
Download
Short summary
In this study, we mixed a pure mineral dust sample with ice active biological material and quantified the immersion freezing behavior of the resulting particles utilizing the Leipzig Aerosol Cloud Interaction Simulator (LACIS). Furthermore, we used different methods to investigate the mixing state of our generated aerosol. We found that internally mixed particles, containing ice active biological material, follow the ice nucleation behavior observed for the pure biological particles.
In this study, we mixed a pure mineral dust sample with ice active biological material and...
Citation
Share