Sublimation occurs on snow covered mountains.

Sublimation occurs on snow-covered mountains

Here are some of the cold and snow-covered mountains of western Canada. What parts of the water cycle are at work at the top of these mountains, at a place where you certainly won't find any liquid water? Many mountains are snow covered all year, so if it never rises above freezing, how does snow not build up forever on these peaks?

A part of the water cycle called sublimation is at work. Just as evaporation turns liquid water into water vapor gas, sublimation turns frozen water directly into water vapor gas, skipping the melting phase into a liquid. Also, as with evaporation, the sun's heat causes sublimation to work, and on top of these mountains on a clear day, the sun is very strong and provides energy for sublimation, even though it is below freezing. Sublimation doesn't just occur on moutain peaks. If there is snow and ice buildup in your neighborhood then on a sunny and dry day sublimation is happening there, too.