Precipitation are particles of water
Precipitation is group of water particles in a liquid or solid state, which from air fall to the ground. Formed by condensation of the existing humidity. It can be generated directly on the ground, such as frost, dew, frost. They can also arise in the air, in the cloud. From air to ground fell as liquid (rain, drizzle), or frozen water (hail, snow, sleet). After falling to the ground may change physical state. Under-cooled water droplets fall to the ground as liquid water. When hitting the ground is frozen to form the ice. To come to that size of individual condensed particles must exceed a certain value. That could in some form of precipitation again fall to the ground. Falling to the ground it is closed water cycle (hydrological cycle). The frequency and average rainfall are characteristic of the relevant geographical areas. The factor that determines the local climate.
The basic division Precipitation:
- Horizontal - dew, frost, frosting, ice- Vertical - rain, drizzle, snow, ice, hail, sleet
Terms of occurrence of precipitation:
- The presence of atmospheric moisture (water vapor) as a result of evaporation.
- The process of condensation mainly as a result of the dynamic cooling.
- The presence of condensation nuclei (solid particles) are hygroscopic particles (ocean salt). The process of condensation begins. Thats before the air becomes saturated. Non-hygroscopic particles are dust, ash and smoke particles. Process of condensation is caused by a certain level of saturation.
Classification precipitation:
- Convective precipitation are caused by rapid heating of air in contact with the ground (reduced density). Water vapor rises and dynamically cools, condenses. It is the formation of a precipitate.
- Orographic precipitation is mechanical lifting horizontal humid air currents (evaporation mountain ranges). As a result of cooling to form a precipitate.
- Cyclonic precipitation resulting from the movement of air masses from areas of high pressure (anticyclone) and an area of low atmospheric pressure (cyclone). As a result of cooling to form a precipitate.
Legality of the spatial distribution of rainfall:
- In the hills, rainfall depends on the direction of air flow (windward, leeward).
- Land regions have less rainfall than the sea, on the same latitude (maritime climate, continental air).
- A large amount of rainfall near the equator and the temperate latitudes replaced with a small amount of precipitation in the tropics, away from the equator and the polar regions (tropics, subtropics, the area of moderate climate, polar air).
- In the tropics, the eastern parts of the tropical sea are humid all year. Western parts are wet only in summer and autumn.
Types of Precipitation:
Rain - drops with diameters greater than 0.5 mm.
Drizzle - precipitation of liquid drops which are less than 0.5 mm in diameter, floating in the air, fall from stratus.
Snow - temperature of about -12 ° C. Water vapor is condensed on the fine ice crystals, which can then bind the snowflakes.
Sleet - ice granules of irregular shape size 2-5 mm. Containing air and can occur due to strong winds in the cold front.
Hail - frozen raindrops diameter greater than 5 mm. They are formed from a single crystal of ice as a core and around the multiple layers of frozen shell. They arise when the storm clouds meet with strong vertical air movements. Repeated creates around them a layer of water which then freezes.
Drizzle - water vapor, which condenses at night on plants or other objects, in tiny droplets.
Hoar - water vapor, which freezes the plants or objects.
Thunder is a collection of sounds that occur as a result of consecutive lightning or scattered sound of distant thunder. Thunder is result of rapid expansion of overheated air through which lightning just passing. From a distance, a flash of lightning is seen before thunder is heard.