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Stefan-Boltzmann Equation
The amount of energy radiated from a body (such as the earth or a
cloud) per unit area per unit time is given by the Stefan-Boltzmann
equation given in Figure 1. The emissivity is a property of
the radiating object, but its value is usually near 1. The
Stefan-Boltzmann constant has a value of 5.6696 x 10-8 Wm-2deg-4. The
effective radiating temperature must be expressed using the Kelvin
temperature scale (0 K being absolute zero and 273 ) for this
formula to make any sense. The fact that the temperature is raised to the
fourth power means that even a small change in temperature translates into
a large change in radiated energy.
NEXT: Review from Previous Units
