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Cloud Formation - Coggle Diagram
Cloud Formation
Types of Clouds
CUMULIFORM: flat bases, most often form when air is heated through contact with surface, produce precipitation.
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CIRRUS: wispy, consist of tiny ice crystals, form at a high altitude, do not produce precipitation so no influence on water cycle.
Clouds have TOPS because once the parcel of air has cooled to the same temp as the surrounding atmosphere, it becomes stable and stops rising.
Clouds have BOTTOMS because unstable air rising reaches the dew point where condensation occurs to begin cloud formation.
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Air Masses
Stable air masses - free from convection / other disturbances, poor visibility as particles can stay in the air, often have stratiform clouds or fog, continuous precipitation as clouds have time to settle.
Unstable air masses - good visibility except in blowing obstructions, weather is variable, cumuliform clouds, showery precipitation.
Condensation - phase change of vapour to liquid water, occurs when air is cooled to its dew point.
In the atmosphere, the change in temperature with height is called the environmental lapse rate (ELR). Its average value is around 6.5ºC/1000m of height gained.
Dew Point - critical temperature at which condensation occurs (varies according to pressure and humidity)
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DRY ADIABATIC LAPSE RATE: rate of change of temp that unsaturated air experiences when it rises adiabatically. (As it rises, no energy is gained or lost to surroundings so temp change caused by air parcel expanding.)
SATURATED ADIABATIC LAPSE RATE: rate of change that a saturated air parcel (cannot hold any more water vapour) experiences.