Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds

AMS Citation:
Schnaiter, M., and Coauthors, 2016: Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds. Atmospheric Chemistry and Physics, 16, 5091-5110, doi:10.5194/acp-16-5091-2016.
Date:2016-04-25
Resource Type:article
Title:Cloud chamber experiments on the origin of ice crystal complexity in cirrus clouds
Abstract: This study reports on the origin of small-scale ice crystal complexity and its influence on the angular light scattering properties of cirrus clouds. Cloud simulation experiments were conducted at the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber of the Karlsruhe Institute of Technology (KIT). A new experimental procedure was applied to grow and sublimate ice particles at defined super- and subsaturated ice conditions and for temperatures in the -40 to -60°C range. The experiments were performed for ice clouds generated via homogeneous and heterogeneous initial nucleation. Small-scale ice crystal complexity was deduced from measurements of spatially resolved single particle light scattering patterns by the latest version of the Small Ice Detector (SID-3). It was found that a high crystal complexity dominates the microphysics of the simulated clouds and the degree of this complexity is dependent on the available water vapor during the crystal growth. Indications were found that the small-scale crystal complexity is influenced by unfrozen H₂SO₄ / H₂O residuals in the case of homogeneous initial ice nucleation. Angular light scattering functions of the simulated ice clouds were measured by the two currently available airborne polar nephelometers: the polar nephelometer (PN) probe of Laboratoire de Métérologie et Physique (LaMP) and the Particle Habit Imaging and Polar Scattering (PHIPS-HALO) probe of KIT. The measured scattering functions are featureless and flat in the side and backward scattering directions. It was found that these functions have a rather low sensitivity to the small-scale crystal complexity for ice clouds that were grown under typical atmospheric conditions. These results have implications for the microphysical properties of cirrus clouds and for the radiative transfer through these clouds.
Peer Review:Refereed
Copyright Information:Copyright 2016 Authors. This work is distributed under the Creative Commons Attribution 3.0 License.
OpenSky citable URL: ark:/85065/d73j3fkq
Publisher's Version: 10.5194/acp-16-5091-2016
Author(s):
  • Martin Schnaiter
  • Emma Järvinen
  • Paul Vochezer
  • Ahmed Abdelmonem
  • Robert Wagner
  • Olivier Jourdan
  • Guillaume Mioche
  • Valery Shcherbakov
  • Carl Schmitt - NCAR/UCAR
  • Ugo Tricoli
  • Zbigniew Ulanowski
  • Andrew Heymsfield - NCAR/UCAR
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