exam 3 review

Upslope fog

caused by air cooling when it is forced uphill, often occurring on mountain slopes

Dewpoint

temperature at which air becomes saturated and condensation begins

Specific humidity

the mass of water vapor to the total mass of the air

Adiabatic lapse rate

the rate at which air cools as it rises without exchanging energy with its surroundings

Constant value for unsaturated lapse rate

10C/km

Clouds

forms when unstable air rises, cools adiabatically, and reaches an altitude where its temperature equals that of the surrounding air

Saturated lapse rate

cooling causes condensation which releases latent heat that warms the air as it rises

What happens to the environmental lapse rate (ELR) if natural lands are replaced with urban development?

ELR becomes steeper, indicating more unstable conditions

Humidity

How much water vapor is in the atmosphere

vapor pressure

amount of pressure contributed by water vapor

Relative humidity

how much water vapor relative to capacity

Fog

forms when cool air mixes with the warm moist air over a surface, the moist air cools until its humidity reaches 100%

Stratus

layer or sheet like clouds

Cirrus

thin wispy clouds

Cumulus

puffy cotton-ball like clouds, some have great vertical development

Nimbus

precipitating clouds

Altitude, composition, appearance, and precipitation type

How are clouds named?

Ice crystals

What are high clouds made of due to very cold temperatures?

Precipitation

any form of water (liquid or solid) that falls from the atmosphere to the earth

Requirements for cloud formation

humid air (water vapor), condensation nuclei, and cooling temperatures

Supercooled water

water that is very cold (below freezing) but still in liquid state. Occurs in the cloud when the droplets are too small to be dropped or no ice nuclei

Cumulonimbus

vertical development, can produce rain showers or thunderstorms

They initiate the formation of ice crystals by providing a surface for water vapor to deposit

What role do ice nuclei play in the cloud?

Cirrostratus

a high ice cloud in layer

Altocumulus

middle level cumulus

Nimbostratus

a layered cloud that is precipitating

Unstable air

Air that has a tendency to rise

Stable air

Tends to remain in its original position or if forced to rise will tend to sink

Condensation

change of water vapor into a liquid

Condensation nuclei

small particles or aerosol upon which water vapor attaches to initiate condensation