Final answer:
Small supercooled water droplets can exist at temperatures as low as -10°C in clouds without freezing. To induce precipitation, methods like cloud seeding and dispersal of dry ice are used to provide nuclei around which water can crystallize and form raindrops.
Step-by-step explanation:
In clouds, small supercooled water droplets persist down to lower temperatures compared to larger droplets. Supercooled liquid water droplets can exist in the atmosphere down to about -10°C without freezing. These droplets require a nucleus to facilitate aggregation into larger droplets capable of falling as precipitation. Methods like cloud seeding introduce particles such as silver iodide to serve as nuclei, while dispersing dry ice can cool water droplets further, causing them to crystallize and create nuclei for raindrop formation.
The phenomenon of supercooling is crucial to understanding Earth's climate, especially in managing precipitation in arid regions. The use of solid CO₂, or dry ice, which sublimes at 1 atm and absorbs heat during sublimation, is an effective method for inducing the formation of ice crystals that act as nuclei for growing raindrops.