4.4, 4.5, 4.8: Atmosphere, Wind Patterns

atmosphere

The mixture of gases that surrounds earth. Broken into 5 distinct layers.

Troposphere

The lowest layer of Earth's atmosphere; where most of earth's weather occurs

Stratosphere

The second-lowest layer of Earth's atmosphere. Contains beneficial ozone (O3) molecules that block UV radiation.

Mesosphere

The 3rd layer of Earth's atmosphere; immediately above the stratosphere

Thermosphere

The outermost layer of Earth's atmosphere. It is by far the thickest layer of earth's atmosphere. It blocks harmful X-ray and UV radiation, and the northern lights (aurora borealis) occur in this region

Exosphere

The outer layer of the thermosphere, extending outward into space.

Hadley Cell

Convection Currents that cycle between the equator, 30 degrees North and South. Warm air at equator rises, cools & expands, rains, spreads out, and then sinks back down to earth @ 30 degrees North & South

Coriolis effect

The effect of Earth's rotation on the direction of winds and ocean currents. Deflects winds to the left between 0 and 30 degrees; to the right between 30 and 60 degrees

Trade winds

prevailing winds that blow from east to west between the equator and 30 degrees N & S

Westerlies

prevailing winds that blow from west to east between 30 and 60 degrees N & S

Equator

An imaginary circle at 0 degrees latitude, halfway between the North Pole and the South Pole; where the suns rays strike earth most directly

rain shadow effect

High precipitation on the windward side of a mountain range, resulting in lush vegetation & a warm, moist climate on that side, but a desert area on the leeward (opposite from the wind) side.

ITCZ (intertropical convergence zone)

A region of low pressure near the equator where air masses meet. Also known as the doldrums.

Air Property: Moisture

Warm air holds more moisture than cold air

Air Property: Density

Warm air is less dense than cold air, so it rises

Air Property: Pressure

As air rises, it is under less atmospheric pressure, so it expands and cools