(Percipitation)Brett Morrow

Precipitation is any form of water that falls to the earth's surface. This includes snow, rain, sleet, freezing rain, and hail.
Precipitation is caused when a mass of warm, moist air hits a mass of cold air. Condensation causes the moisture to form droplets that become rain or crystals that become snow or ice. When these droplets or crystals become too heavy to be suspended in the atmosphere, they fall to Earth as precipitation.


History of (Percipitation)

Raindrops grow in size primarily because water exists in all three phases in the atmosphere and because the air is supersaturated at times (especially with respect to ice) because of adiabatic expansion and
radiation cooling. This means that ice crystals coexist with liquid water droplets in the same cloud. The difference in the vapor pressure between the water droplets and the ice crystals causes water droplets to evaporate and then to sublimate directly onto the ice crystals. Sublimation is the process whereby water vapor changes into ice without passing through the liquid stage. Condensation alone does not cause droplets of water to grow in size. The turbulence in cloud permits and aids this droplet growth processes. After the droplets become larger, they start to descend and are tossed up again in turbulent updrafts within the cloud.

Application of (Percipitation)

Measuring precipitation covers rain, hail, snow, rime, hoar frost and fog, and is traditionally measured using various types of rain gages such as the non-recording cylindrical container type or the recording weighing type, float type and tipping-bucket type.One of the critical components of the Earth's hydrological cycle is precipitation. Rainfall is essential for providing the fresh water that sustains life. Some say the first rain gauge was invented more than 2,000 years ago when rulers of the Choson Dynasty (now Korea) decreed that all villages were to engage in measuring precipitation. The rainfall data was then incorporated into a formula to determine the potential harvest of each farm.


  1. http://www.tpub.com/content/aerographer/14312/css/14312_138.htm
  2. http://www.global-greenhouse-warming.com/measuring-precipitation.html
  3. (Ref #3 - from book, library, journal)

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