1. Introduction to the Atmosphere

2. Earth's Atmosphere An envelope of air surrounding the planet Earth.
How would you define air?
What's it made of?

3. Air is a mixture of solids, liquids, and mostly gases.

4. Gases in the Atmosphere
Permanent Gases:
Nitrogen (N2): 78%
Oxygen (O2): 21%
Argon (Ar): 0.9%
Carbon Dioxide (CO2): 0.04%
Water Vapor (H2O): %
Trace Gases (others): 0.01%

5. Variable Gases Water Vapor (H2O) Carbon Dioxide (CO2) Ozone (O3)
Others

6. Atmospheric pressure decreases with increasing height
Atmospheric pressure decreases with increasing height. Since most of the atmosphere's molecules are held close to the earth's surface by the force of gravity, air pressure decreases rapidly at first, then more slowly at higher levels.

7. Layers of the Atmosphere
Troposphere
Weather, jets fly here.
Stratosphere
Ozone Layer
Mesosphere
Meteors burn up here
Thermosphere
Ionosphere and Northern Lights
Very few particles
Exosphere
Transition from atmosphere to space

8. What does the atmosphere do for us?
Earth's atmosphere acts as an insulating layer that protects the earth's surface from the intense light and heat of the sun. 
Contains oxygen, which we and other living organisms breathe.
Medium of transport for various chemicals, including, but not limited to, water (in the form of rain, snow, steam, etc), carbon dioxide and oxygen (for cycling of these chemicals between plants and animals), and nitrogen (which helps plants grow).