Solar Radiation and the
Radiation: all forms of energy that travel through
space as waves
Ex: visible light, ultraviolet, infrared (heat), x-rays, etc.
The molecules of nitrogen and oxygen in the upper atmosphere
(mesosphere and thermosphere) absorb the short wavelengths of
x-rays, gamma rays, and ultraviolet rays
- (about 20% of solar energy that reaches our atmosphere)
- The small amount of ultraviolet radiation that does reach the earth’s
surface causes sunburn
We are protected
Most of the solar radiation that reaches the lower atmosphere is
visible or infrared.
- About 50% of solar energy is absorbed by the land and
- About 30% is reflected back into space
***The type of surface determines whether absorption or
reflection takes place
the process by which the atmosphere traps infrared rays over the
- the sun heats the earth’s surface (long wavelengths);
- the heat is then given off by the ground and heats the
air (shorter wavelengths)
1. Light and heat come in.
2. Light escapes, heat is trapped.
The greenhouse effect is necessary to keep Earth warm…However…
- Carbon dioxide is a greenhouse gas
- The amount of CO2 has been increasing
-> more heat will be trapped & the average temp will
rise (global warming)
The Greenhouse Effect
Choices Need to be Made