Water ice clouds are clouds composed of ice crystals, forming in specific atmospheric conditions on planets.
Formation and Characteristics
Water ice clouds primarily form in the mesospheres of terrestrial planets, including those in our solar system and likely beyond. The formation process involves:
- Vapor Deposition: Water vapor directly transforms into ice crystals, bypassing the liquid phase.
- Low Pressures and Temperatures: This process occurs under extremely low atmospheric pressures and temperatures.
- Crystalline and Amorphous Ice: Depending on the conditions, the ice can form in various crystalline structures or as amorphous (non-crystalline) ice.
| Characteristic | Description |
|---|---|
| Location | Mesospheres of terrestrial planets (and likely elsewhere) |
| Formation Process | Vapor deposition at low pressures and temperatures |
| Ice Phases | Crystalline and amorphous |
Therefore, water ice clouds are not simply clouds made of water droplets that have frozen. Their formation process and location differentiate them from other types of clouds.
