Stochastic homogeneous freezing of supercooled droplets in mixed-phase clouds in particle-based idealised microphysics framework (exemplified with PySDM v3.0)

Lüttmer, Tim; Arabas, Sylwester; Spichtinger, Peter

doi:10.5194/gmd-19-10185-2026

Articles | Volume 19, issue 20

https://doi.org/10.5194/gmd-19-10185-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

The tropopause region in a changing atmosphere (TPChange)...

https://doi.org/10.5194/gmd-19-10185-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 20

Model description paper

|

27 Oct 2026

Model description paper |

| 27 Oct 2026

Stochastic homogeneous freezing of supercooled droplets in mixed-phase clouds in particle-based idealised microphysics framework (exemplified with PySDM v3.0)

Tim Lüttmer, Sylwester Arabas, and Peter Spichtinger

Supplement

https://doi.org/10.5194/gmd-19-10185-2026-supplement

Data sets

Stochastic homogeneous freezing of supercooled droplets in mixed-phase clouds in particle-based idealised microphysics framework (exemplified with PySDM v3.0) T. Lüttmer https://doi.org/10.5281/zenodo.22080761

Model code and software

Stochastic homogeneous freezing of supercooled droplets in mixed-phase clouds in particle-based idealised microphysics framework (exemplified with PySDM v3.0) T. Lüttmer https://doi.org/10.5281/zenodo.22080761

Short summary

Homogeneous freezing describes the spontaneous freezing of supercooled droplets, with the probability depending on temperature, droplet size, and elapsed time. Droplets freeze across a range of temperatures rather than all at once, and faster updrafts and larger droplets lead to freezing at warmer temperatures. Once some droplets freeze, the growing ice crystals deplete the surrounding vapour, causing the remaining droplets to evaporate. This affects the number of ice crystals in the cloud.