THE EARTH’S ATMOSPHERE:Atmospheric Layers

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Shirley Enríquez

Earth AtmosphereThe atmosphere of Earth is the layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects lifeon Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducingtemperature extremes between day and night (the diurna temperature variation).

Structure of the Atmosphere

• Exosphere

• Thermosphere

• Mesosphere

• Stratosphere

• Troposphere

Exosphere

• The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km (6,200 mi; 33,000,000 ft). The exosphere merges with the emptiness of outer space, where there is no atmosphere.

• The exosphere is located too far above Earth for any meteorological phenomena to be possible. However, the aurora borealis and aurora australis sometimes occur in the lower part of the exosphere, where they overlap into the thermosphere. The exosphere contains most of the satellites orbiting Earth.

Thermosphere

• The thermosphere is the outermost layer of the Earth’s atmosphere.

Thermosphere• It begins at 80

km (50 miles) above the Earth and extends outward into space.

• Sometimes the thermosphere and exosphere are listed as separate layers.

Thermosphere

• The higher you move in this layer, the higher the temperature.

• Temperatures in the thermosphere can reach 1,800°C (3,300°F)!

Thermosphere

• The beautiful colors of the aurora borealis or northern lights occur in this atmospheric layer.

Thermosphere

• This is also where the space shuttle orbits the Earth!

Thermosphere

Mesosphere

• The mesosphere begins at about 50 kilometers (31 miles) above the Earth’s surface and extends to 80 kilometers (50 miles).

Mesosphere

• As you move up into the mesosphere, the air temperature decreases.

• Temperatures at the top of this layer can drop to -90°C (- 130°F ).

Mesosphere

• Interestingly, this layer also protects the Earth.

• Meteoroids entering Earth’s atmosphere usually burn up in the mesosphere.

Stratosphere• The stratosphere

begins at the top of the troposphere (14 km/ 9 miles) and extends to about 50 kilometers (31 miles) above the surface of the Earth.

Stratosphere

• As you move up into the stratosphere the air temperature actually increases.

Stratosphere

• The ozone layer/ ozonosphere is located at the bottom of the stratosphere.

Troposphere

• The troposphere is the lowest layer of the atmosphere that lies next to the Earth’s surface.

Troposphere

• Most of the air that makes up the atmosphere is found in the troposphere.

Troposphere

• It extends to about 14 kilometers (around 9 miles) above the Earth

• and is where virtually all weather takes place.

Troposphere

• As you move up into the troposphere the temperature decreases.

• At the top of this layer the air temperature is about - 60°C (-76° F).