Precipitation, in
meteorology, is any type of
water that falls from the sky as
weather. This includes
snow,
rain,
sleet,
freezing rain and
hail. Precipitation is a major part of the
water cycle[?], and is responsible for depositing most of the fresh water on the planet. Precipitation is generated in
clouds, which reach a point of saturation; at this point larger and larger droplets (or pieces of
ice) form, which then fall to the earth under
gravity. It is possible to 'seed' clouds to induce precipitation by releasing a fine dust or appropriate chemical (commonly
silver nitrate) into a cloud, encouraging droplets to form, and increasing the probability of precipitation.
In chemistry, precipitation is the condensation of a solid from a solution. This occurs when the solution is saturated, whereupon the solid forms, and usually sinks to the bottom of the solution.
See also umbrella.