Friday, December 19, 2014

Global Warming:Degrees of Heat Transfer

Radiation is the transfer of energy between two objects by electromagnetic waves. Heat radiates from the ground into the air of the atmosphere.

In conduction, heat moves from areas of more heat to areas of less heat by direct contact. Warmer molecules vibrate rapidly and collide with other nearby molecules, transferring their energy. In the atmosphere, conduction is more effective at lower altitudes, where air density is higher. This transfers heat upward to where the molecules are spread further apart or transfers heat laterally from a warmer to a cooler spot, where the molecules are moving less vigorously.

Heat transfer by movement of heated fluids and air is called convection. Heat that radiates from the ground initiates convection in the atmosphere

Note: I save good money by applying the use of thermal insulation in my home. The walls and attic are the obvious places insulated to slow down the ‘conduction’ of heat. The double pane windows are also provided with a thermal barrier. Argon fills the air space between the double panes. It slows down the transfer of heat by slowing the rate of heat ‘convection’.

In the atmosphere, the 'solar' shortwave radiation that has hit and warmed the Earth's surface becomes 'thermal' long wave radiation that tries to escape to space. Increased levels of greenhouse gases decreases the degree of heat transferability of the atmosphere. At historically natural levels, greenhouse gases are a good thing. But at increasingly unnatural levels, they become problematic.

Transfer of Heat Energy:

Heat Transfer In The Atmosphere:

Earth’s Energy Budget:'s_energy_budget

Greenhouse Effect: