On the thermodynamic and kinetic aspects of immersion ice nucleation
<p>Heterogeneous ice nucleation initiated by particles immersed within droplets is likely the main pathway of ice formation in the atmosphere. Theoretical models commonly used to describe this process assume that it mimics ice formation from the vapor, neglecting interactions unique to the...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/17119/2018/acp-18-17119-2018.pdf |
| Summary: | <p>Heterogeneous ice nucleation initiated by particles immersed
within droplets is likely the main pathway of ice formation in the
atmosphere. Theoretical models commonly used to describe this process assume
that it mimics ice formation from the vapor, neglecting interactions unique
to the liquid phase. This work introduces a new approach that accounts for
such interactions by linking the ability of particles to promote ice
formation to the modification of the properties of water near the
particle–liquid interface. It is shown that the same mechanism that lowers
the thermodynamic barrier for ice nucleation also tends to decrease the
mobility of water molecules, hence the ice–liquid interfacial flux.
Heterogeneous ice nucleation in the liquid phase is thus determined by the
competition between thermodynamic and kinetic constraints to the formation
and propagation of ice. At the limit, ice nucleation may be mediated by
kinetic factors instead of the nucleation work. This new ice nucleation
regime is termed spinodal ice nucleation. The comparison of predicted nucleation
rates against published data suggests that some materials of atmospheric
relevance may nucleate ice in this regime.</p> |
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| ISSN: | 1680-7316 1680-7324 |