1. DO NOW: COPY THIS IN COMP BOOK
Objectives:
Describe the Earth’s atmosphere.
Identify three methods of heat transfer.
Explain the greenhouse effect.
Key Terms:
Ozone
Radiation
Conduction
Convection
Greenhouse Effect

2. Key Terms
Ozone
Radiation
Conduction
Convection
Greenhouse Effect

3. The Atmosphere Mixture of gases that surround Earth.
Gases can be added to and removed through:
living organisms
volcanic eruptions

4. The Atmosphere Insulates Earth’s surface.
Regulates Earth’s temperature allowing living organisms to survive.

5. Composition of the Atmosphere
N2 – Most abundant gas
from volcanoes and decay.
O2 – Second most abundant gas
mostly by plants.

6. Composition of the Atmosphere
Other gases
argon
carbon dioxide
methane
water vapor
Also contains particulates.

7. Air Pressure in Atmosphere
Atmosphere is denser near the Earth’s surface due to gravity.

8. Layers of the Atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere

9. Layers of the Atmosphere

10. Troposphere Temperature drops as altitude increases.
Weather conditions exist here
Most dense layer

11. Stratosphere Above troposphere Temperature drops as altitude increases
Ozone layer is contained in stratosphere.

12. Stratosphere - Ozone Ozone = O3. Absorbs UV radiation
Reduces radiation that reaches Earth.
UV radiation damages cells.

13. Mesosphere Above the stratosphere. Coldest layer of atmosphere
Temperatures can reach –93ºC.

14. Thermosphere N2 and O2 absorb solar radiation 2,000+ ºC.
Atoms become charged (ions)
Lower layer - ionosphere
Ions radiate energy as light (Northern Lights)
Least dense layer

15. Northern Lights

16. Layer of the Atmosphere
Graphic Organizer
Layer of the Atmosphere
Characteristics

17. Energy Transfer in the Atmosphere
Radiation - energy transferred directly through space.
Example: Sunlight

18. Energy Transfer in the Atmosphere
Conduction - energy transferred as heat through a material.
Example: spoon in a cup of soup

19. Energy Transfer in the Atmosphere
Convection - movement of matter due to differences in temperature
results in transfer of energy as heat.

20. The Movement of Energy in the Atmosphere
Air currents - caused by differences in temperature (density) in atmosphere.
The continual cycling of warm/cool air (or water) = convection current.

21. Energy Transfer in the Atmosphere

22. Heating of the Atmosphere
Solar energy reaches Earth as electromagnetic radiation

23. Heating of the Atmosphere
Oceans and land radiate absorbed energy back into the atmosphere.
Dark objects absorb more solar radiation than light objects.

24. Greenhouse Effect
Sunlight penetrates atmosphere (warms surface of Earth).
Greenhouse gases (CO2, methane, and nitrous oxide) and water vapor absorb some radiation (rest is lost to space).
Causes warming of the surface and lower atmosphere of Earth
Necessary for life to exist.