Air Masses & Weather Flashcards
What is an air mass?
A body of air with similar internal characteristics that is distinct from the surrounding air.
What characteristics are used to qualify an air mass?
Moisture and Temperature
What are the symbols used for moisture?
m for maritime = wetter
c for continental = drier
What symbols are used for temperature?
P = Polar T = Tropical
What are the 4 Atmospheric Lifting Mechanisms?
Convergent
Convectional
Orographic
Frontal
What is a cold front?
As cold air approaches, the cold air pushes up the warm air quickly. Wind shifts, the temperature drops and pressure increases. Cold fronts can create short-lived, violent storms.
What is a warm front?
Warm air pushes over cooler air like a wedge. Gentle lifting, stratiform clouds develop and Nimbostratus gentler, more persistent rainfall occurs.
Describe Convergent Lifting
Air flows from different directions (converges) in a low pressure system. Is the source of heavy rains in the tropics.
Describe Convectional Lifting
Air rises because it moves over a hotter land mass (moves from a maritime source to a warmer continental region). Occurs with mT and mP air over continental areas with unstable conditions.
Describe Orographic Lifting
Lifting as air mass is forced over a mountaintop.
What is a Chinook wind?
Also called foehn winds, they are winds with a descending slope that are higher and drier than when they ascended.
What is a Rain Shadow?
Dry regions on the leeward side of mountains
Contrast windward vs. leeward
Windward = wetter intercepting slop Leeward = drier far-slide slope
Define weather
short-term atmospheric conditions
Mesocyclone vs Tropical Cyclone
Mesocyclone = Tornado
Tropical Cyclone = Hurricane/Typhoon
