Information AboutInsolation |
| CATEGORIES ABOUT INSOLATION | |
| atmospheric radiation | |
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(top) and at the planet's surface.]] Insolation is a measure of Solar Radiation incident on a surface. It is the amount of solar energy received over a given area in a given time. It is commonly expressed in kilowatt-hours per square meter per day (kW•h/m2/day) or watts per square meter (W/m2). The surface may be a planet or a terrestrial object inside the atmosphere, or any object exposed to solar rays including Spacecraft . Some of the solar radiation will be absorbed, causing radiant heating of the object, and the remainder will be reflected. The proportion of radiation reflected or absorbed depends on the object's Reflectivity or Albedo . PROJECTION EFFECT The insolation into a surface is largest when the surface directly faces the Sun. As the angle increases between the direction normal to the surface and the direction of the rays of Sunlight, the insolation is reduced in proportion to the Cosine of the angle. This is known in optics as '' Lambert's Cosine Law ''. This 'projection effect' is the main reason why the Polar Region s are much colder than Equatorial Region s on Earth. On an annual average the poles receive less insolation than does the equator, because at the poles the Earth's surface is angled away from the Sun. EARTH'S INSOLATION Direct Insolation is the solar radiation that is transmitted directly through the atmosphere to the earth's surface without interacting with atmospheric components. Diffuse Insolation is the solar radiation that is scattered or reflected by atmospheric components. |
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