Radiation, Conduction, Convection

Heat Transfer Processes 1._____________ - Sun heats Earth’s surface in the form of rays or waves 2._____________ - Earth’s warm surface heats lower atmosphere by direct contact 3._____________ - heat is distributed by warm air rising and cold air sinking Radiation Conduction Convection

Radiation The transfer of heat energy by electromagnetic radiation. Solar energy reaches Earth by radiation. Earth is heated by this process. various substances on earth (dirt, rocks, water, concrete, sand, etc.) absorb this energy and their heat level is raised.

Conduction The transfer of heat energy from one substance to another through contact. The air touching the Earth’s surface is heated due to conduction.

Convection The transfer of heat energy through a circular motion of a fluid. Commonly seen in the kitchen when you see boiling water Air in the atmosphere acts a fluid

Questions If you feel the heat in the handle of a cooking pot, that heat was transferred to the handle by: A.) Convection B.) Conduction C.) Radiation Answer: Conduction

Questions A sunburn is caused by which method of heat transfer: A.) Radiation B.) Convection C.) Conduction D.) Visible Light Answer: Radiation

Transfer of Heat Energy Summary 1.Radiation 2.Conduction 3.Convection

3 Ways heat is transferred into the atmosphere… 1.Radiation 2.Conduction 3.Convection

Greenhouse Effect Prevents heat loss mainly from convection (air movement carrying away the heat) The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. Because of how they warm our world, these gases are referred to as greenhouse gases.