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Updated: Jul 12, 2026

Ice Generation and the Heat and Mass Transfer Phenomena of Introducing Water to a Cold Bath of Brine
Published on: March 13, 2017
Solid ammonium sulfate aerosols as ice nuclei: a pathway for cirrus cloud formation
J P D Abbatt1, S Benz, D J Cziczo
1Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada. jabbatt@chem.utoronto.ca
Abstract:
Laboratory measurements support a cirrus cloud formation pathway involving heterogeneous ice nucleation by solid ammonium sulfate aerosols. Ice formation occurs at low ice-saturation ratios consistent with the formation of continental cirrus and an interhemispheric asymmetry observed for cloud onset. In a climate model, this mechanism provides a widespread source of ice nuclei and leads to fewer but larger ice crystals as compared with a homogeneous freezing scenario. This reduces both the cloud albedo and the longwave heating by cirrus. With the global ammonia budget dominated by agricultural practices, this pathway might further couple anthropogenic activity to the climate system.
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