Final answer:
Supercooled water droplets freeze onto falling ice crystals through the process of deposition, which enables the formation of precipitation from clouds.
Step-by-step explanation:
The process by which supercooled water droplets freeze onto falling ice crystals is called deposition. This is an important aspect of cloud physics and is integral to the formation of precipitation. Supercooling occurs when water droplets remain in the liquid state below their normal freezing point, generally down to about -10°C. However, when they come into contact with ice crystals or other nuclei, like dust particles or artificially introduced substances like silver iodide or solid CO₂ (dry ice), they can freeze and subsequently grow in size to form precipitation. When dry ice is used, it sublimates in the cloud, absorbing heat and causing the supercooled droplets to freeze and fall as rain.