Solar Radiation and Solar Radiation and the Greenhouse Effectthe Greenhouse Effect

Earth ScienceEarth Science

Ms. KurtzweilMs. Kurtzweil

Radiation: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 by our atmosphere!

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 oceans

- About 30% is reflected back into space

***The type of surface determines whether absorption or reflection takes place

Global HeatingGlobal Heating

greenhouse effect: the process by which the atmosphere traps infrared rays over the earth’s surface.

- 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 EffectThe Greenhouse Effect

Choices Need to be MadeChoices Need to be Made