What causes some clouds to be snow white? Can they be the source of rain?
Jane Helter, 3rd grade, Chesterton, Ind.
The color of clouds depends mainly on the viewer’s perspective relative to the source of the light that is illustrating the clouds. During the day, sunlight is the only source of light. Much of the sunlight that strikes a cloud reflects off of it. When we see that reflected light, the cloud’s surface appears to be a brilliant white.
All this happens independently of weather conditions underneath the cloud. If we are seeing the brilliant white light reflected from a cumulonimbus cloud, there may be a raging thunderstorm in progress beneath it. If we are looking at small, puffy cumulus clouds — also brilliant white — then the weather at the moment is usually pleasant and dry.