andor/image_lib/lores/introduction/introduction%20(light)/intlight%201%20small.jpg

1. http://www.andor.com/image_lib/lores/introduction/introduction%20(light)/intlight%201%20small.jpghttp://www.andor.com/image_lib/lores/introduction/introduction%20(light)/intlight%201%20small.jpg

2. http://lasp.colorado.edu/cassini/images/Electromagnetic%20Spectrum.jpghttp://lasp.colorado.edu/cassini/images/Electromagnetic%20Spectrum.jpg

3. Energy • All matter above 0K emits Rn in the form of waves • Some objects absorb and emit Rn in certain l only • The l of Rn emitted by a surface depends on the temperature (Wien’s Law): lmax = w = constant T = temperature w T

4. Energy • The higher the temperature of an object, the greater the rate/intensity of Rn emission (Stefan-Boltzmann Law): E = sT4 E = maximum rate of Rn/second s = constant T = temperature

5. Energy • The amount of Rn striking a surface is inversely related to the square of the distance from the source: 1 d2

7. Energy • Solar constant • 1367 W m2 s-1 Absorbed Scattered Reflected

8. Energy THE GREENHOUSE EFFECT Some solar radiation is reflected by the Earth and atmosphere. Some of the infrared radiation passes through the atmosphere, and some is absorbed and re-emitted in all directions by greenhouse gas molecules. The effect of this is to warm the Earth’s surface and lower atmosphere. ATMOSPHERE Solar radiation passes through the clear atmosphere. EARTH Infrared radiation is emitted from the Earth’s surface. Most radiation is absorbed by the Earth’s surface and warms it.

9. Energy

10. Energy

11. Energy

12. Energy a S i = S(1 – a) i = long-term input, S = solar flux, and a = albedo Radiative equilibrium temperature