Immersion freezing of clay minerals and bacterial ice nuclei
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Author(s)
Hiranuma, Naruki
Möhler, Ottmar
Bingemer, Heinz
Bundke, Ulrich
Cziczo, Daniel James
Danielczok, Anja
Ebert, Martin
Garimella, Sarvesh
Hoffmann, Nadine
Hohler, Kristina
Date Issued
2013
Journal
AIP Conference Proceedings
Publisher
American Institute of Physics (AIP)
Citation
Hiranuma, Naruki, Ottmar Möhler, Heinz Bingemer, Ulrich Bundke, Daniel J. Cziczo, Anja Danielczok, Martin Ebert, et al. “Immersion Freezing of Clay Minerals and Bacterial Ice Nuclei” Nucleation and Atmospheric Aerosols: 19th international conference, Fort Collins, Colorado, USA, 23-28 June 2013. AIP Conf. Proc. 1527, 914 (2013). © 2013 AIP.
Version
Final published version
Abstract
The immersion mode ice nucleation efficiency of clay minerals and biological aerosols has been investigated using the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber. Both monodisperse and polydisperse populations of (1) various clay dust samples as well as (2) Snomax® (a proxy for bacterial ice nucleators) and (3) hematite are examined in the temperature range between −4°C and −35°C. The temperature dependence of ice formation inferred by the INAS (Ice Nucleation Active Surface-Site) density is investigated and discussed as a function of cooling rate and by comparing to predicted nucleation rates (i.e., classical nucleation theory with θ-probability density function nucleation scheme). To date, we observe that maintaining constant AIDA temperature does not trigger any new ice formation during the immersion freezing experiments with clay dust samples and Snomax®, implying strong temperature dependency (and weak time dependency) within our time scales and conditions of experiments. Ice residuals collected through a newly developed PCVI (Pumped ounter-flow Virtual Impactor) with the 50% cut size diameter of 10 to 20 μm have also been examined by electron microscope analyses to seek the chemical and physical identity of ice nuclei in clay minerals. In addition to the AIDA results, complementary measurements with mobile ice nucleation counters are also presented.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
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DOI of Published Version
https://doi.org/10.1063/1.4803420
