Air Masses Flashcards

Air mass: A large body of air with similar temperature and humidity properties both horizontally and vertically.
Source regions: Typically flat, uniform, and dominated by high pressure, characterized by light winds.

Continental air masses: Form over land, dry due to lack of moisture.
Maritime air masses: Form over water, moist and can influence weather significantly.

Continental Polar (cP): Cold and dry, associated with winter weather in North America.
Continental Arctic (cA): Extremely cold and dry, leading to severe winter conditions.
Continental Tropical (cT): Hot and dry, often responsible for summer heat waves.
Maritime Polar (mP): Cold and moist, causing damp weather particularly along the northeastern U.S. coast.
Maritime Tropical (mT): Warm and humid, leading to muggy conditions in the eastern U.S. during summer.

Air masses are modified after leaving their source regions, yet retain distinctive properties for several days.
Temperature classifications include tropical (T), polar (P), and arctic (A).
Moisture classifications include maritime (m) for moist air from oceans and continental (c) for dry air from land.

Maritime Tropical (mT): Wet and warm, influences weather from the Gulf of Mexico and Caribbean, can produce heavy rainfall.
Continental Tropical (cT): Hot and dry; prevalent in summer, originating from southwestern deserts.
Maritime Polar (mP): Cool and moist, following cold fronts into California.
Continental Polar (cP): Cold and dry, triggers severe winter weather across the eastern U.S.

Air masses typically move up in summer and down in winter, affecting regional climates.

Cold air masses like cA or cP can gain moisture when moving over warmer ocean waters during winter, leading to instability.
These changes affect the air mass symbol, adding 'k' for colder conditions and 'w' for warmer.

As maritime polar (mP) air crosses mountain ranges, it becomes modified, resulting in relatively dry conditions on the eastern side of the Rockies.

Occurs when a cold air mass moves over warm water, primarily in autumn and early winter.
Cold continental polar (cP) air absorbs moisture from warmer waters, leading to heavy snowfall once it cools over land.