AOSC 123 Lecture Notes - Lecture 6: Radiant Energy, Longwave, Wave Power
22 Feb 2016
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Document Summary
Fundamental law of radiation: all objects that have a temperature above zero degrees kelvin with emit radiation. Stefan boltzman law: the amount of energy per square meter per second that is emitted by an object is related to the 4th power of its kelvin temperature. The earth also emits radiation called terrestrial or long wave radiation which is less energetic than solar radiation and therefore characterized by longer wavelengths. Wien"s displacement law: temperature of the emitting body affects the wavelength of the maximal radiant energy emitted: the hotter an object, the shorter the wavelength of maximum emission. Basic climate model: average earth temperature is -18 degrees celsius actually 15 degrees celsius in reality. The greenhouse effect causes the actual value of surface temperature to be higher. Absorb part of the radiant energy that passes through and radiate it back to. Spectrophotometry: uses photometers that can measure a light beam"s intensity as a function of its color.
