1. Earth’s Atmosphere Notes to be written are in red font.
You DO NOT have to write anything else.

2. Atmospheric Composition
What exactly is Air?
Air used to be thought of as a “vital spirit.”
All cultures had their own understanding
of air, whether it be an element of purity,
spiritual energy, a deity, or one of
Aristotle’s classical elements (earth, fire,
water, air) that everything is made up of.
In your notes take 1 minute and
describe air without using the
word gas.

3. Atmospheric Composition
Air is made up of gas and particulates.
Test your knowledge from yesterday
and take 1 minute to write down what
gases are in our air.

4. Atmospheric Composition
Gasses in our air:
Nitrogen (N2)= 78%
Oxygen (O2)= 21%
Other = 1%
Argon
Carbon Dioxide
Water vapor
Neon
Helium
Methane
Nitrous Oxides
Ozone

5. Atmospheric Composition
Last year you learned how volume and pressure apply to gas. Look at the
pictures above as you copy down the laws below.
Boyle’s Law: Pressure of a gas decreases when the volume increases. +
Charles Law: Volume of the gas increases or decreases as temperature increases or decreases
= Ideal gas Law: The state of an amount of gas is determined by its pressure, volume, and temperature.

6. Atmospheric Composition
Even though air is mostly made up of lighter elements in gas form located above the surface of the Earth, it also contains tiny particles that you can see.
Particulates – Very small airborne liquid or solid particles that cause air pollution

7. Atmospheric Composition
Types of particulates:
Dust
Fumes
Mist
Smoke
Aerosols

8. Atmospheric Composition
Effects of Dust
While “dusting” can be a chore or in high concentrations, it is considered a type of pollution, there are good benefits of dust.
Benefits of Dust
Causes rain and snow (nucleation points)
Filters sunlight (reflects sunlight away from Earth)
Helps make the sky blue (scattering of light waves)

9. Air Pressure/Density
Pause and look at this picture while you read through this slide. Air is made up of molecules – therefore, it has mass. Anything with mass is subject to a gravitational force.
Gravity shapes all atmospheric processes.
Density and pressure decrease as altitude increases.
Climbing to an altitude of only 5.5 km where the pressure is 500 mb, would put you above one-half of the atmosphere’s molecules.

10. Air Pressure/Density
Air pressure - The amount of atmospheric force exerted over a surface area
Air density is
the number of air molecules in a given space (volume).
Air pressure ↓ as altitude ↑.
Air pressure ↓ as water vapor ↑ .
(Moist air is less dense than dry air. WHY?)

11. Air Pressure/Density
The ordinary pressure of the air surrounding us is 14.7 pounds per square inch. However, this pressure is always fluctuating as the wind blows, or even as an object like a car accelerates. Scientists use a barometer to measure atmospheric pressure.

12. Atmospheric Structure
Differences in density creates layers in the atmosphere.

13. Atmospheric Structure
Layers of the atmosphere include:
Troposphere
Temperature decreases
Stratosphere
Temperature increases in the upper layer
Mesosphere
Thermosphere
Temperature increases

14. Atmospheric Layers Where space shuttles orbit Earth.
Where weather forms and storms take place.
Troposphere
Stratosphere
Mesosphere
Thermosphere
Where space shuttles orbit Earth.
Auroras take place in the Ionosphere,
located in the lower region of the thermosphere
Where shooting stars blaze.
Meteors or rock fragments burn up in this layer.
Where the protective ozone layer is located.

15. The Stratos Jump!
Red Bull Stratos was a space diving project involving Austrian skydiver Felix Baumgartner – Oct. 14, 2012.