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Updated: Jul 3, 2026
12:11
Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Volume versus surface nucleation in freezing aerosols
Omar F Sigurbjörnsson1, Ruth Signorell
1Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1.
Summary
Current aerosol freezing studies cannot distinguish between volume and surface nucleation mechanisms due to experimental limits. This ambiguity significantly impacts atmospheric modeling accuracy.
Area of Science:
- Atmospheric Chemistry
- Physical Chemistry
- Nanoparticle Science
Background:
- Aerosol freezing is critical for cloud formation and climate.
- Distinguishing between volume and surface nucleation mechanisms remains a challenge.
- Existing droplet ensemble measurements have limitations in resolving these mechanisms.
Purpose of the Study:
- To investigate the ambiguity in distinguishing volume versus surface nucleation in freezing nanosized aerosol particles.
- To assess the impact of experimental uncertainties and kinetic analysis approximations on nucleation mechanism determination.
- To highlight the consequences of this ambiguity for atmospheric process modeling.
Main Methods:
- Utilized state-of-the-art measurements of droplet ensembles.
- Analyzed the kinetics of aerosol freezing.
- Quantified uncertainties arising from experimental factors and analytical approximations.
Main Results:
- Demonstrated that current droplet ensemble measurements cannot differentiate between volume and surface nucleation.
- Identified inherent experimental uncertainties and kinetic analysis approximations as key limitations.
- Showed that these factors can lead to two orders of magnitude uncertainty in rate constants.
Conclusions:
- The distinction between volume and surface nucleation in freezing aerosols is not resolvable with current ensemble measurement techniques.
- Significant uncertainties in nucleation rate constants arise from experimental and analytical limitations.
- These uncertainties have substantial implications for the accuracy of atmospheric models.
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