1. Atmosphere: Section 1- Earth’s Atmosphere

2. What is the Atmosphere made of????
Mixture of :
Gases
Solids
Liquids

3. How was the Early atmosphere much different from today?
Volcanoes produced nitrogen and carbon dioxide, but little oxygen.
More than 2 billion years ago simple organisms began producing oxygen.
Eventually, oxygen formed an ozone layer that protected Earth from harmful rays
Green plants and diverse life forms developed

4. Gases
Includes all of the gases in the Atmosphere.
What type of mixture is the atmosphere?
Atmosphere is changing with the introduction of pollutants: increasing human energy use is increasing the amount of Carbon Dioxide
Pollutants mix with oxygen and other chemicals to form smog.

5. Include dust, salt and pollen
Solids
Include dust, salt and pollen

6. Water droplets and Droplets from volcanoes
Liquids
Water droplets and Droplets from volcanoes

7. Five main Layers of the atmosphere
Lower Layers:
Troposphere : The layer where humans live. It extends about 10 km up, and contains most of the water vapor and gases.
Stratosphere: Extending from about 10 km to 50 km above Earth. It contains the ozone.
Upper Layers:
Mesosphere: extends from 50 km to 85km and is the layer in which meteors are visible.
Thermosphere: Thickest part of the atmosphere; from 85 km to 500km. Has high temperatures.
Ionsphere: Layer of charged particles. Helps carry radio waves.
Exosphere: Outer layer of atmosphere in which the space shuttle flies, has very few molecules.

8. Question time……………
What is the layer of the atmosphere nearest to Earth’s surface?
Which layer in the atmosphere is warmed by the heat from Earth’s surface?
Describe temperatures in the thermosphere.

9. Atmospheric Pressure
Molecules closer to the surface or more densely packed (at higher pressure) that those higher in the atmosphere because of the mass of gases pressing down from higher in the atmosphere.

10. As altitude increases, pressure decreases
Atmospheric Pressure
As altitude increases, pressure decreases
What happens when we climb a mountain? Why?
What happens when we are swimming at the bottom of a deep pool? WHY?

11. Atmospheric Pressure
Observing the effects of Air pressure …… Demonstration Section 1: Enrichment Lab Sheet

12. TEMPERATURE IN ATMOSPHERIC LAYERS
Troposphere: warmed primarily by the Earth’s surface; temperature decreases at altitude in creases
Stratosphere: Temperature increase as as altitude increases--- mainly the upper portion because Ozone absorbs energy from the Sun.
Mesosphere: Temperatures decrease with altitude.
Thermosphere and Exosphere: 1st to receive the Sun’s rays extremely warm

13. Ozone
About 19km to 48 km above Earth in the atmosphere, this layer of 2-atom-oxygen molecules (O3) protects the Earth from the Sun’s harmful ultraviolet radiation.
Life depends on it
Pollutants called chlorofluorocarbons (CFCs) are destroying the ozone layer.
Are used in refrigerators, air conditioners, aerosol sprays, and foam packaging.
The ozone layer has a large hole over Antarctica

14. What is the Ionosphere and where is it located?
Discussion Question
What is the Ionosphere and where is it located?
Where is air pressure the greatest? Why
Why are chlorofluorocarbons harmful to the ozone?
How does the atmosphere prevent some radiation from reaching Earth’s surface?