1. Introduction to the Atmosphere
The air around us.
Intro:
National Geographic : Our Atmosphere Earth Science

2. Surface of Earth There are 4 layers on Earth’s surface:
Lithosphere: solid, rocky crust covering Earth
Hydrosphere: all water on Earth
Atmosphere: the air that surrounds Earth
Biosphere: composed of all living organisms

3. What is the atmosphere?
It controls temperature, protects us from harmful ultraviolet rays from the sun, and supports life.

4. Composition of the Atmosphere
The majority of the composition
of the atmosphere is:
21% OXYGEN (O2)
78% NITROGEN (N2)
0.04% CARBON DIOXIDE(CO2)
~0.9% ARGON (Ar)

5. Layers of the Atmosphere

6. TheTroposphere Troposphere: The closest layer to Earth.
Weather and clouds occur in here.
The temperature generally decreases as altitude increases.

7. The Stratosphere The 2nd layer from the earth.
The earth's ozone layer (absorbs ultraviolet rays) is located here.
Aircrafts fly in this layer, too.

8. The Troposphere vs. the Stratosphere

9. The Mesosphere The 3rd layer from the earth.
Meteors burn up while entering this layer.
Temperatures drop with increasing altitude

10. The Thermosphere Fourth layer from the earth.
Air particles in this layer are electrically charged enabling radio waves to bounce back to earth.
Northern lights (aurora) is formed in this layer too.
Temperature increases with altitude but pressure is so low that it is hard to feel it.

11. The Exosphere The last layer of the atmosphere.
Particles in that layer move into and from space.
** Your textbook does not mention this layer**