Transmitting Energy To The SurfaceRemember the solar constant idea from the solar energy section? That value is how scientists measure the amount of energy that reaches the surface of the Earth from the Sun. The energy amount is based on that constant. If all of the energy hit the surface, the value would be "1." If none of it hit the surface, the value would be "0". There are factors that affect the amount of energy hitting the surface.
A List o'Factors(1) How cloudy is it? The number of clouds that are overhead, their thickness, and density are major factors in energy transmission. As it becomes cloudier, less energy is able to hit the surface of the planet.
(2) How high up are you? The altitude of the ground is very important. This is a logical idea. If you are higher up, there will be less atmosphere to absorb incoming energy. It's a shorter distance from the mountaintop to the upper layer of the atmosphere. Higher altitudes receive greater amounts of incoming radiation.
(3) How much water vapor is in the air? It's all about humidity for this factor. A greater amount of water vapor in the air is able to absorb more IR radiation heading for the surface. While some of the atmosphere may become warmer, the energy hitting the surface decreases.
(4) How much dust and dirt is in the air? Dust and dirt act like cloud cover. The clouds of dust after the explosion of a volcano block out the Sun and its energy.
But Wait... There's More!Think about day length. On shorter days there is less time for the energy to reach the Earth at some places. That fact means there will be less energy put into the systems of that location. You also have to think about the time of year. Depending on the time of year, the Sun is lower and higher in the sky. Think about winter. The higher north or south you are, the lower the Sun is. That location means less light is hitting the ground directly from the Sun. Less light means less energy.
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- EM Spectrum
- Solar Radiation
- Global Geometry
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The Greenhouse Effect (NASA Earth Observatory Video)
Useful Reference MaterialsEncyclopedia.com (Energy):
Wikipedia (Energy Transfer):
Encyclopædia Britannica (Surface Energy Budget):