Convection

1
Convection

• Convection in Air
• Investigation 5, Part 3

2
Convection in the atmosphere

• Sun shines on a large parking lot
• The blacktop absorbs some of the radiant energy
• What might happen to the part of the atmosphere
  close to the parking lot?

3
Convection Chamber
Ice represents the cold temperatures of the
atmosphere
Candle represents a hot location on earths
surface
Smoke allows you to see the moving air
4
Convection Chamber

• After observing the convection chamber draw a
  diagram showing the movement of smoke and air in
  the chamber on page 29 of your lab book.
• Answer Part 2 questions.

5
How Convection Occurs?
Smoke loses heat by conduction when it touches
the metal cover
Smoke becomes less dense and rose to the cover
Smoke was colder and more dense, so it sank
Moved across the bottom to the candle where it is
heated
The process repeats itself again and again
6
Convection Cell on Earth
Radiation heats Earths surface
Cool air contracts and becomes more dense
Warm air expands and becomes less dense
Air above surface is heated by conduction and
reradiation
7
Convection Cell

• The cycle of air where warm air expands and
  rises, and then air cools and falls back to Earth.