What process describes water vapor forming on ice crystals in cloud formation?

The process that describes water vapor forming on ice crystals in cloud formation is known as deposition. During deposition, water vapor in the air transitions directly into ice without first becoming liquid water. This process is crucial in the formation of certain types of clouds, particularly those at colder temperatures, such as cirrus clouds, where ice crystals are present.

In the context of cloud formation, when the conditions are right, supercooled water vapor can deposit onto existing ice crystals, causing those crystals to grow. This contributes to the development of clouds in cold environments, where the air temperature is well below freezing. The ability of ice crystals to attract additional water vapor and grow through deposition is an essential aspect of the cloud formation process in colder atmospheres.