Nucleation
Nucleation is a crystallization process. Water needs a solid point to freeze into ice, so pure water drops do not freeze. Once they touch the surface, the drops start freezing immediately.
- ↑ Pruppacher, H. R. et al. (1998) Microphysics of Clouds and Precipitation. Aerosol Science and Technology. [Online] 28 (4), 381–382.
- ↑ Will it rain, sleet or snow?, Weather.Gov, webpage, available (accessed 29.2.2021): https://www.weather.gov/source/zhu/ZHU_Training_Page/winter_stuff/winter_w x/winter_wx.html