1. 17.2
Heating the Atmosphere

2. Heat
The energy transfer from one object to another, due to a difference in temperature.

3. Temperature
Average amount of Kinetic Energy (energy of motion) in a substance
Measured with a thermometer
Units: degrees
(C or F)

4. Conduction: Direct Contact Heat Transfer
Transfer of heat through molecules of a solid
Energy always transfers from HOT → COLD
Least important method of heat transfer in atmosphere.

5. Convection
Transfer of heat through mass movement within a fluid (gas or liquid)
Most heat in troposphere is moved by convection
As fluid is heated it expands, becomes less dense than the fluid around it, and rises, while more dense fluid fills the space left behind.

6. Radiation Travels in all directions from its source.
Unlike convection and conduction, radiation needs no material through which to travel
Objects that are good absorbers of radiant heat are good at emitting radiant heat.

7. Energy from the Sun Energy travels to Earth as electromagnetic waves
Electromagnetic waves can travel through empty space.
Transfer of energy by electromagnetic waves is called radiation

8. All energy from the sun comes through Electromagnetic (EM) Waves
Travels at 300,000 km/sec
The EM Spectrum divides energy according to wavelength

9. Electromagnetic Waves
Ultraviolet radiation has a higher frequency than visible light.
Infrared has a lower frequency than visible light.

10. Visible Light A mixture of colors that you can see
Colors are based on wavelength

11. Infrared Radiation
Energy with wavelengths longer than visible light
Ex: heat lamp for reptiles

12. Ultraviolet Radiation
Energy with wavelengths shorter than visible light
May cause sunburns/cancer (damages DNA)

13. Energy in the Atmosphere: Some is absorbed, some is reflected
Greenhouse gases: CO2, CH4, H2O

15. Why is the sky blue?
Scattering - reflection of light in all directions
Gases scatter more blue light (short wavelength)
This makes the sky appear blue

16. Why Sunsets Are Red.

17. The Greenhouse Effect
Natural process in which gases hold heat in the atmosphere
Infrared radiation is trapped by greenhouse gases
Example: Methane, Water Vapor, Carbon Dioxide

18. Increases in CO2 in the atmosphere is causing an imbalance of the greenhouse effect, and rising temperatures of atmosphere and ocean.