Heterogeneous ice nucleation: exploring the transition from stochastic to singular freezing behavior 1Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany
30 Aug 2011
2Dept. of Physics, Michigan Technological University, Houghton, Michigan 49931, USA
Received: 12 Nov 2010 – Published in Atmos. Chem. Phys. Discuss.: 28 Jan 2011 Abstract. Heterogeneous ice nucleation, a primary pathway for ice formation in the
atmosphere, has been described alternately as being stochastic, in direct
analogy with homogeneous nucleation, or singular, with ice nuclei initiating
freezing at deterministic temperatures. We present an idealized, conceptual
model to explore the transition between stochastic and singular ice
nucleation. This "soccer ball" model treats particles as being covered with
surface sites (patches of finite area) characterized by different nucleation
barriers, but with each surface site following the stochastic nature of ice
embryo formation. The model provides a phenomenological explanation for
seemingly contradictory experimental results obtained in our research groups.
Even with ice nucleation treated fundamentally as a stochastic process this
process can be masked by the heterogeneity of surface properties, as might be
typical for realistic atmospheric particle populations. Full evaluation of
the model findings will require experiments with well characterized ice
nucleating particles and the ability to vary both temperature and waiting
time for freezing.
Revised: 24 Jun 2011 – Accepted: 19 Aug 2011 – Published: 30 Aug 2011
Citation: Niedermeier, D., Shaw, R. A., Hartmann, S., Wex, H., Clauss, T., Voigtländer, J., and Stratmann, F.: Heterogeneous ice nucleation: exploring the transition from stochastic to singular freezing behavior, Atmos. Chem. Phys., 11, 8767-8775, doi:10.5194/acp-11-8767-2011, 2011.