(CP) Unit 2 - Humidity and Clouds 2021_AT

Dew Point

the temperature at which condensation occurs because the air is saturated

Adiabatic Cooling

temperature change that occurs when air expands

Cirrus

high-altitude clouds that are thin, feathery tufts of ice crystals.

Convergence

as air is drawn together at the surface, like when there is a surface low pressure, it causes an upward movement of air.

Cumulus

low altitude thick, puffy, white clouds with flat bases, formed by vertically rising air currents often localized convective lifting or convergence

Condensation Nuclei

microscopic particles on which water vapor condenses to form cloud/fog droplets.

Dew

tiny drops of water that form on cool surfaces when water vapor condenses

Alto

prefix meaning middle altitude in cloud classification

Capacity

the maximum amount of water that can be present in the air at a certain temperature; increases with increasing temperature.

Condensation

the change from water vapor to liquid water

Frost

feathery crystals of ice formed on surfaces when water vapor in the air deposits at a temperature below freezing

Cumulonimbus

a type of cumulus cloud that has vertical development, gray color, and associated with downpours, thunderstorms, tornadoes, hail and cold fronts

Halo

a circle of light around the sun or moon in a cirrostratus cloud

Mare's Tail

type of cirrus cloud with a hook shape that can indicate rain within 24 hours if caused by a warm front

Nimbo

prefix-suffix to indicate that a cloud is rain-bearing

Orographic Lifting

mountains acting as barriers to the flow of air, forcing the air to rise.

Evaporation

the change from liquid water to water vapor

Rain Shadow

an area having relatively little precipitation due to the effect of a physical barrier like a mountain range on the adiabatic cooling and warming of air

Fog

a cloud in contact with the ground

Relative Humidity

a comparison of the actual amount of water vapor in the air with the maximum amount of water vapor that can be present in the air. (Specific Humidity/Capacity)

Saturation

the condition in which the air is holding as much water vapor as possible at a given temperature and pressure. When air is saturated it is also 100% RH and the dewpoint temperature has been reached so there will be condensation.

Specific Humidity

the amount of water vapor in the air at a given time and place; expressed as the number of grams of water vapor per kilogram of air.

Transpiration

the emission of water vapor into the atmosphere from the leaves of plants

Water Vapor

water in its gaseous form

Cloud

a collection of small water droplets or ice crystals suspended in the air

Deposition

phase change from gas to solid

Latent Heat

heat absorbed or radiated during a change of phase

Mountain Wave Cloud

stationary lenticular clouds situated over and downwind of a prominent mountain range

Stratus

clouds that form in low, horizontal layers, covering all or most of sky

precipitation

Any form of water that falls from clouds and reaches Earth's surface.