The Earth’s Atmosphere

Characteristics of the Atmosphere

• The Atmosphere is a mixture of gases that surround the earth • The Atmosphere protects us from

the harmful rays of the sun.

Composition of the Atmosphere

• Besides the main two gases Nitrogen and Oxygen, the atmosphere also contains liquids and small solids

• The most common of the liquids in the atmosphere is water

Atmospheric Pressure

• Air pressure is the measure of the force with which the air molecules push on a surface

• As you move farther from the earth’s surface (lithosphere)

the air pressure decreases.

Pressure• The Atmosphere is held in its position by the

gravity of the earth • Gravity pulls the gas molecules towards the

earth which gives them weight • As you move farther from the earth the air

pressure decreases

• Altitude is the height of an object above the earths surface

Air Temperature

• As you pass through the atmosphere, air temperature changes to warmer or colder conditions

Layers of the Atmosphere• The Earth’s atmosphere is divided into five

layers- the troposphere , the stratosphere, the mesosphere, the thermosphere, and the exosphere

Troposphere

• the layer of the atmosphere nearest Earth’s surface

• where all weather occurs• temperature is warmest near the ground

and decreases as you go higher, (as altitude increases, temperature decreases )

Stratosphere

• Is very thin and contains little moisture

• Is extremely cold (-60 degrees Celsius)

• The ozone layer which absorbs the harmful rays of sunlight is found here• Jets fly here

Mesosphere

• Is the coldest layer of the atmosphere (-93° C)

• Meteors burn up in this layer

Thermosphere

• Temperatures can reach 2,000 degrees Celsius

• The temperature here is dependent on solar activity.

• Auroras occur in this layer

Exosphere

• Different regions of this layer make long distance communication possible• Satellites found here

A way to remember the layers of Earth’s Atmosphere!

• Troposphere• Stratosphere• Mesosphere• Thermosphere• Exosphere • That Snail Missed The Exit!