Air Masses, Fronts, and Cyclones Flashcards
What is meant by Pineapple Express?
It refers to the warm moist air coming from the Pacific ocean
Frontal system
Is when warm air (from equator) collides with cold air (from the poles) creating extreme weather conditions like blizzards
Air parcel
Is a given volume of air
Air Masses
Are large bodies of air with fairly uniform temperature and moisture characteristics
Air Masses are based on the:
- Latitude in which they are forming (tropical, polar, Arctic, Antarctic)
- Surface type (marine (moist), continental (dry)
Continental Arctic Properties
Cold, dry, stable
Continental Polar Properties
Dry, cold, stable
Maritime Polar Properties
Moist, cool, unstable
Continental Tropical
Dry, warm, unstable
Frontal Lifting:
When boundaries between air of unlike temperatures (fronts) migrate, the warmer air is pushed a lot
What is the result of frontal lifting?
Adiabatic cooling and cloud formation
Cold Front
Is when cold air advances towards warm air and warm air is displaced vertically by cooler air which usually forms a line of clouds or thunderstorms (squall line)
Warm Front
Are generally slower than cold fronts, as the warm air gently overrides the cold air, stratiform clouds form
Occluded fronts
Is when a faster moving cold front overtakes a warm front, leading to precipitation
Cyclone:
Is a low pressure system
A cyclone in the northern hemisphere spins…
Counter-clock wise
Stages of mid-latitude cyclones:
- Early stage
- Open stage
- Occluded stage
- Dissolving stage
Dissolving Stage
Is the lifting of warm air which ceases causing the cyclone to lose its source of energy and moisture
Occluded stage
When a cold front overtakes warm front, forcing warm air aloft and causing precipitation
Open Stage
Warm air moves north along advancing front, and the cold air moves south
Early stage/ Cyclogenesis
The convergence of cold, polar air and warm subtropical air wand war air masses
