APES
Module 10—Air Currents
Name __________________________
Why does warm air have a lower density than cold air?
The unequal heating of Earth affects climates because it determines regional _____________________ and it drives the
_____________________ of air around the planet.
Atmospheric Convection Currents
Air has four properties that determines its movement:
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(1) Density—the density of air determines its _____________________
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-less dense air _____________________, denser air ____________________
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Why does warm air rise?
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(2) Water vapor capacity- warm air has a _____________________capacity for water vapor than cold air.
The maximum amount of water vapor in the air is __________________________________________
When the temperature of air falls, its saturation point _____________________, water vapor
_____________________ and _____________________ happens
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(3) response to changes in _____________________
Adiabatic heating or cooling- as air rises in the atmosphere its pressure _____________________and
the air _____________________. Conversely, as air sinks, the pressure _____________________and
the air _____________________in volume.
(4) Latent heat release- when water vapor in the atmosphere condenses into liquid water and energy is
_____________________.
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Formation of Convection Currents
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Atmospheric convection currents are global patterns of air movement that are initiated by the
_____________________heating of Earth.
Air warmspressure ______________________ air _____________________ _____________________
atmospheric pressure _____________________ cooling condensation and _____________________
_____________________ release air _____________________  air _____________________ more
_____________________ atmospheric pressure _____________________ cooling _____________________
displacement and sinking _____________________ atmospheric pressure _____________________ warming
Hadley cells- the convection currents that cycle between the equator and _____________________ north and south.
Why are regions at 30oN and 30oS hot, dry deserts?
Intertropical convergence- the area of Earth that receives the _____________________sunlight and where the
_____________________branches of the two Hadley cells converge.
Polar cells- the convection currents that are formed by air that rises at 60˚ north and south and sinks at the
_____________________ (90˚ north and south)
Ferrell cell—a convection current in the atmosphere that lies between _____________________ and
_____________________
Describe each process:
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Earth's Rotation and the Coriolis Effect
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As Earth rotates, its surface moves much faster at the equator than in mid-latitude and polar regions.
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The faster rotation speeds closer to the equator cause a deflection of objects that are moving directly north or
south.
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Earth's Rotation and the Coriolis Effect
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Coriolis Effect- the deflection of an object's path due to Earth's rotation.
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The prevailing winds of the world are produced by a combination of atmospheric convection currents and the
Coriolis effect.
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Earth's Tilt and the Seasons
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The Earth's axis of rotation is tilted 23.5 ˚.
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When the Northern Hemisphere is tilted toward the Sun, the Southern Hemisphere is tilted away from the Sun,
and vice versa.