1. Thermal Energy Transfer
in the Atmosphere
Thermal Energy Transfer

2. What is Thermal Energy Transfer?
There are three types of thermal energy transfer:
Radiation
Conduction
Convection

3. Radiation
Heat transfer by radiation is the transfer of heat through electromagnetic waves.

4. Radiation
There is no direct contact between the substances.

5. Radiant Energy from the sun radiates through
empty space to earth.

6. Radiant Energy from the sun consists of :
Visible Light
Ultraviolet Light- has a shorter wavelength than visible light and can cause sunburn and skin cancer
Infrared Radiation- has longer wave length than visible light and is felt as heat

7. ENERGY ON EARTH
Not all of the sun’s energy reaches the Earth’s Surface.
20% of the Sun’s Energy is ABSORBED by gases and particles in the Atmosphere.
Ozone, Oxygen & Water Vapor absorb ultraviolet light
Water and carbon dioxide(CO2) absorb infrared light.
Earth’s Atmosphere (clouds) and the surface of the Earth REFLECTS about 30% of Sun’s radiation
About 50% of the Sun’s radiation is absorbed by the Earth's Surface

9. RADIATION BALANCE
Earth’s temperature remains stable because of the balance between the amount of radiation coming from the Sun and the amount going out from Earth.
Land, trees, and the oceans absorb and emit solar radiation mainly in the form of infrared radiation.

10. THE GREENHOUSE EFFECT
Glass allows sunlight into a green house. It prevents infrared radiation from escaping which keeps the greenhouse warm

11. THE GREENHOUSE EFFECT
Certain gases, such as CO2, in the atmosphere act like the glass in a greenhouse warming the atmosphere.

12. What is Thermal Energy Transfer?
Thermal energy transfer is the movement of heat energy from one substance to another.
Heat (energy) always moves from objects with high temperature to objects with low
Cold
Hot

13. What is Thermal Energy Transfer?
Heat will continue to move until both substances are the same temperature.
Warm
Warm

14. What is Thermal Energy Transfer?
The greater the difference in temperature between the substances, the faster the heat will transfer.

15. Your Coke becomes cold because the heat from the soda
Your Coke becomes cold because the heat from the soda
transfers into the ice, not the other way around.

16. No matter what it feels like, cold does not transfer into your body.
What is really happening here?
Why do you wear heavy clothes when it’s cold outside?

17. Examples Anti-Examples
You touch a black car in the summer and the heat from the car transfers into your hand.
A breeze makes you feel cooler because the wind transfers heat away from your body.
You feel the cold of a winter day because the cold air transfers into you.
Your Coke in a cooler gets cold because the cold from the ice moves into the Coke.

18. Conduction
The transfer of thermal energy by the collisions between particles of matter. (through direct contact).
Molecules transfer energy to the molecules next to them.

19. Conduction The molecules do not have to be the same substance.

20. Conduction
Thermal energy is CONDUCTED from the warm ground to the air above it.

21. cooler air, forming a convection current.
As air above the road warms up, it becomes less dense and rises and is replaced by
cooler air, forming a convection current.

22. Convection
Heat transfer by convection is the transfer of thermal energy (heat) through the fluid (liquids and gases) movement of currents.

23. Convection
Warm fluids rise, cool down, sink, and then are warmed again.

24. The radiator warms the room by warming the
The radiator warms the room by warming the
air around it. Then the warm air transfers heat
to the rest of the room through convection.

25. When water changes from one phase to another, Latent heat is exchanged.

26. This picture illustrates all three type of heat transfer.
This picture illustrates all three type of heat transfer.
Can you identify them all?

27. Conduction Convection Radiation