|Heat builds up during the
day because the amount of visible and infrared (IR) radiation from sunlight
exceeds the amount of long wavelength infrared radiation (IR) re-radiated
and lost from the earth's surface. Therefore, the earth's surface warms
up, which in turn warms up the air next to the earth, thus the air temperature
increases close to the earth's surface.
|The earth's surface slowly
looses heat by re-radiating long wavelength infrared (IR) radiation, thus
the solid objects of the earth's surface cool. This in turn decreases the
air temperature next to the earth's surface. If enough energy is
lost to drop the temperature below freezing, a frost occurs. Thus,
a freezing layer of air occurs next to the earth's surface with a warmer
layer of air just above it (about 10-15 feet), which results in the development
of a temperature inversion.
The conditions for this to occur are: a) night, b) no wind, and c) no cloud cover.