APESName ______

Module 10—Air Currents

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:

•(1) Density—the density of air determines its ______

•-less dense air ______, denser air ______

•Why does warm air rise?

•(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

•(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 ______.

Formation of Convection Currents

•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:

•Earth's Rotation and the Coriolis Effect

•As Earth rotates, its surface moves much faster at the equator than in mid-latitude and polar regions.

•The faster rotation speeds closer to the equator cause a deflection of objects that are moving directly north or south.

•Earth's Rotation and the Coriolis Effect

•Coriolis Effect- the deflection of an object's path due to Earth's rotation.

•The prevailing winds of the world are produced by a combination of atmospheric convection currents and the Coriolis effect.

•Earth's Tilt and the Seasons

•The Earth's axis of rotation is tilted 23.5 ˚.

•When the Northern Hemisphere is tilted toward the Sun, the Southern Hemisphere is tilted away from the Sun, and vice versa.