How is heat transferred throughout the earth?

Questions• What do you know about heat?

• What are some sources of heat?

• Does heat move? If yes, what makes you think it does move? How does it move from place to place?

• Where does heat come from and where does it go?

Demo Time

• The demo shown will describe three different ways heat is transferred within the earth’s atmosphere.

• Write an analogy on how the demo helps explain the movement of heat in the atmosphere with what you know from the demo.

Conduction

• Definition: transfer of heat through a solid, liquid or gas by direct contact.

• Think of examples of something in real life where energy would be transferred from something to you.

• Where did that happen in the demo?

Convection

• Definition: transfer of heat by the actual movement of the warmed matter. The heat moves with the fluid.

• Think of examples of something in real life where energy would be transferred from something to you.

• Where does it happen in the demo?

Radiation• Definition: transfer of energy by

electromagnetic waves through space (air).

• Think of examples of something in real life where energy would be transferred from something to you.

• Where does it happen in the demo?

Demo

• Remember at the beginning of the demo we dropped in food coloring. Once the food coloring was dropped in it started to swirl around in the water.

• Where does Radiation,Conduction and Con-vection take place?

Examples

Examples

Other Examples:

• Conduction: walking barefoot on hot pavement, grabbing of a hot handle of pan

• Convection: feeling the heat coming out of a heat duct in your house when you are sitting across the room from it, when cooking pasta: as it gets warmer it moves to the top of the pan while the cooler water stays on the bottom and then circulates eventually in the pan.

• Radiation: feeling the heat from a campfire, feeling the heat of the sun when you go outside.

How does this relate to weather?• Air in the atmosphere acts as a fluid. The sun's RADIATION

strikes the ground, thus warming the rocks. As the rock's temperature rises due to CONDUCTION, heat energy is released into the atmosphere, forming a bubble of air which is warmer than the surrounding air. This bubble of air rises into the atmosphere. As it rises, the bubble cools with the heat contained in the bubble moving into the atmosphere.

• As the hot air mass rises, the air is replaced by the surrounding cooler, more dense air, what we feel as WIND. These movements of air masses can be small in a certain region, such as local cumulus clouds, or large cycles in the troposphere, covering large sections of the earth. CONVECTION currents are responsible for many weather patterns in the troposphere.