1. The Atmosphere

2. Atmosphere
Definition: the layer of gases that surrounds the Earth
Weather is the condition of Earth’s atmosphere at any given time or place

3. What gases are in our atmosphere?
nitrogen (N2) = 78%
oxygen (O2)= 21%
trace gases= 1%
argon
CO2
neon
methane
krypton
hydrogen

4. What are some sources of carbon dioxide (CO2) in our atmosphere?
burning fossil fuels releases CO2
into the atmosphere
Greenhouse Effect- CO2 and other gases act as a blanket to hold in heat close to Earth

5. What else is in our atmosphere?
Water vapor - from evaporation and transpiration (1 tree gives off 40,000 gallons of water vapor in a year!)
Solid particles (particulate matter) - dust, smoke, pollen, salt, pollutants from car exhaust, burning and volcanic eruptions

6. Ozone O3 - a form of oxygen with 3 atoms of oxygen instead of 2
the layer of ozone
in the atmosphere
absorbs UV
radiation from
the sun and heats
the Earth

7. Learn more about the Ozone layer:

8. Air pressure
Definition - the weight of a column of air pushing down on an area
More dense air has higher air pressure than less dense air.
Barometer - an instrument used to measure air pressure

9. Air pressure Animation

10. Units for measuring air pressure
Inches of mercury - used
with a mercury barometer
Millibars - used on National
Weather
Service maps

11. Altitude Definition - the distance above sea level
The higher the altitude the lower the air pressure.
Animation:

12. Notes Quiz What is the most abundant gas in our atmosphere?
2. What are some trace gases that are in our atmosphere? (name 3)

13. 3. What is ozone? a) liquid oxygen b) oxygen molecule with 3 atoms of oxygen instead of 2 c) a form of rust
4. What are some of the solid particles in air? (Name 4)

14. 5. Why would there be more water vapor in a tropical rain forest than in a desert? a) the climate is wet in a rain forest and a lot of water would evaporate b) there would be a lot of transpiration from the trees c) both a and b

15. 6. What is air pressure?
7. In what 2 units is it measured?
8. How is air pressure affected by density?
9. How is air pressure affected by altitude?
10. Name one source of carbon dioxide in our atmosphere.