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Updated: Jul 12, 2026
08:16
Ice Generation and the Heat and Mass Transfer Phenomena of Introducing Water to a Cold Bath of Brine
Published on: March 13, 2017
Surface crystallization of supercooled water in clouds.
A Tabazadeh1, Y S Djikaev, H Reiss
1National Aeronautics and Space Administration Ames Research Center, Earth Sciences Division, Moffett Field, CA 94035, USA. atabazadeh@mail.arc.nasa.gov
Summary
Homogeneous ice nucleation in cloud droplets is not well understood. This study suggests that ice formation at the air-liquid interface, rather than the droplet
Area of Science:
- Atmospheric Chemistry
- Physical Chemistry
- Cloud Physics
Background:
- The homogeneous crystallization of liquid cloud droplets into ice is a poorly understood process.
- Current theories suggest homogeneous freezing initiates within the droplet's interior volume.
- Experimental data on homogeneous freezing rates exhibit significant scatter, varying by orders of magnitude.
Purpose of the Study:
- To investigate the role of the air-liquid interface in homogeneous ice nucleation.
- To explain the discrepancies in experimental ice nucleation rates observed in different ambient phases.
- To elucidate the reasons for the limited supercooled water observed in the atmosphere near -40°C.
Main Methods:
- Experimental investigation of ice nucleus formation at the air-liquid water interface.
- Comparison of freezing rates in different ambient phases (air vs. oil emulsion).
- Analysis of supercooled water observations in atmospheric conditions.
Main Results:
- Ice nucleus formation at the air-liquid interface provides a plausible explanation for variable experimental ice nucleation rates.
- Surface crystallization can account for the observed differences in freezing rates across various ambient phases.
- The findings suggest a mechanism for the limited presence of supercooled water in the atmosphere around -40°C.
Conclusions:
- Ice nucleation at the air-liquid interface is a critical factor influencing homogeneous freezing in cloud droplets.
- This interfacial process reconciles discrepancies in experimental data and atmospheric observations.
- Understanding surface crystallization is key to accurately modeling cloud droplet freezing and atmospheric water.
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