1. Earth is surrounded by a mixture of gases known as the Atmosphere

2. Composition of the Atmosphere
Nitrogen – 78%
Oxygen – 21%
Other – 1% (Argon, CO2, Water Vapor, others)

3. Air Pressure
Earth’s atmosphere is pulled towards Earth’s surface by gravity. Thus, the atmosphere is denser at the surface and less dense at higher altitudes.

4. Layers of the Atmosphere
Troposphere- closest
to the Earth’s surface.
Where our weather
occurs.

5. Layers of the Atmosphere
Stratosphere – 2nd
layer. Contains the
Ozone layer.

6. Layers of the Atmosphere
Mesosphere- 3rd
layer, helps in
protecting us from
meteors.

7. Layers of the Atmosphere
Thermosphere –
Farthest from the
Earth’s surface.
Warmest layer,
Interactions with
solar radiation causes
the aurora borealis.

8. Energy in the Atmosphere

9. Energy in the Atmosphere
About 50 % of incoming solar energy is absorbed by Earth’s surfaces.
About 50% is reflected back into space in the form of low level infrared radiation.

10. Energy Transfer in the Atmosphere
Radiation – the transfer by waves
Convection – the transfer by air movement
Conduction- the transfer by the touching of one object to another

11. Greenhouse Effect
The process by which gases trap heat near the Earth’s surface.