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: 5.509 IF 5.509
  • IF 5-year value: 5.689 IF 5-year 5.689
  • CiteScore value: 5.44 CiteScore 5.44
  • SNIP value: 1.519 SNIP 1.519
  • SJR value: 3.032 SJR 3.032
  • IPP value: 5.37 IPP 5.37
  • h5-index value: 86 h5-index 86
  • Scimago H index value: 161 Scimago H index 161
Volume 15, issue 16
Atmos. Chem. Phys., 15, 9159-9171, 2015
https://doi.org/10.5194/acp-15-9159-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 15, 9159-9171, 2015
https://doi.org/10.5194/acp-15-9159-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 19 Aug 2015

Research article | 19 Aug 2015

Laboratory studies of collection efficiency of sub-micrometer aerosol particles by cloud droplets on a single-droplet basis

K. Ardon-Dryer, Y.-W. Huang, and D. J. Cziczo K. Ardon-Dryer et al.
  • Dept. of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts, USA

Abstract. An experimental setup has been constructed to measure the collection efficiency (CE) of sub-micrometer aerosol particles by cloud droplets. Droplets of a dilute aqueous ammonium sulfate solution with an average radius of 21.6 μm fall freely into a chamber and collide with sub-micrometer polystyrene latex (PSL) sphere particles of known sizes and concentrations. Two relative humidity (RH) conditions, 15 ± 3 % and 88 ± 3 %, hereafter termed "low" and "high", respectively, were varied with different particles sizes and concentrations. After passing through the chamber, the droplets and aerosol particles were sent to the Particle Analysis by Laser Mass Spectrometry (PALMS) instrument to determine chemical compositions on a single-droplet basis. "Coagulated droplets" (droplets that collected aerosols) had mass spectra that contained signatures from both an aerosol particle and a droplet residual. CE values range from 2.0 × 10−1 to 1.6 for the low-RH case and from 1.5 × 10−2 to 9.0 × 10−2 for the high-RH case. CE values were, within experimental uncertainty, independent of the aerosol concentrations. CE values in this study were found to be in agreement with previous experimental and theoretical studies. To our knowledge, this is the first collection experiment performed on a single-droplet basis with atmospherically relevant conditions such as droplet sizes, droplet charges and flow.

Publications Copernicus
Download
Short summary
The collection between aerosol and a water droplet is an important mechanism for removing particles from the atmosphere, and has an influence on cloud dynamics, precipitation processes and cloud lifetime. In this experiment, the collection process was studied on a single-droplet basis, with atmospherically relevant conditions (droplet sizes, charges and flow). Collection efficiency values were found to be in agreement with previous experimental and theoretical studies.
The collection between aerosol and a water droplet is an important mechanism for removing...
Citation
Share