1. The Sun Supplies Atmosphere with Energy
Unit A Chapter 1 Section 2

2. Where does almost all of the energy around you come from?
The sun

3. What are the two main things that happen to sunlight that reaches Earth’s surface?
Reflected (bounces off) back into atmosphere
Absorbed (soaked into) Earth’s surface.

4. What is radiation?
Energy that travels across distances in the form of waves
Examples: visible light, infrared radiation, and ultraviolet radiation

5. What happens when certain gases absorb infrared radiation?
Warms the air

6. What is conduction?
Transfer of energy from one substance to another by direct contact.
Examples:
The hot pot handle makes your hand hot
Your feet get hot when you walk barefoot on hot sand

7. What is convection?
Transfer of energy from place to place by the motion of a gas or liquid
Example: warmed air rises up and carries heat to the cat on the shelf

8. In the atmosphere, what direction is the usual motion of convection?
Up and down
Warm air carries the energy up in the atmosphere
When the air cools off, it sinks back to the ground

9. What produces the motion of air convection?
Differences in density of the air
Low density air
High density air
Low density air
High density air

10. What causes changes in density of air at the same altitude?
Changes in temperature
Warm air rises and cool air sinks
Warm air expands and has fewer particles per cubic inch than cool air
This makes warm air less dense than cool air

11. What causes the air temperature to change with altitude?
Different parts of the atmosphere absorb and move energy in different ways

12. What criteria do scientists use to define the 4 layers of the atmosphere?
Patterns of temperature change in the atmosphere

13. Layers of the atmosphere From Earth’s Surface to Outer Space
Exosphere/outer space

14. Layers of the atmosphere Farthest from Earth: Thermosphere – 90 km or 56 mi above the Earth
Atmosphere grows less and less dense until it becomes outer space
Air is hot because it absorbs solar radiation
Auroras occur here

15. Layers of the atmosphere Next Layer Down: Mesosphere – 50 to 90 km or 31-56 mi above the Earth
Below Thermosphere
Air is very thin – very few molecules of air
Most meteors burn up here
Heated from below by the stratosphere so the temperature goes down as you up go up in altitude

16. Layers of the atmosphere Next Layer Down: Stratosphere – 10 to 50 km or 6-31 mi above Earth
Below Mesosphere
Above troposphere
Ozone layer found here
Absorbs solar radiation so the temperature increases as you go up in altitude

17. Layers of the atmosphere Closest to Earth: Troposphere – 0 to 10 km or 0-6 mi. above the Earth
Nearest layer to the Earth – where you live
Warmed by the ground so the temperature goes down as you go up in altitude
Contains 80% of the atmosphere’s mass
Includes all the water vapor
Most weather happens here
Jet Streams found at top of this layer.

18. Layers of the Atmosphere

19. A1.2 Reflection/Homework
THIS WILL BE CHECKED!
Compare and contrast conduction, convection, and radiation. (You might use a three circle Venn diagram and/or include pictures, write a paragraph, or etc.)
Draw a picture that shows all three forms of energy transfer in the atmosphere. Include the direction convection usually moves in the atmosphere and why. Label your drawing.

20. A1.2 Reflection/Homework