1. CH 3: The Electromagnetic Spectrum
What wavelengths are associated with sunburns?
What wavelengths ‘break’ NO2?
What types of transitions are important for UV, VIS, IR, Microwave?

2. CH 3: The Electromagnetic Spectrum
Top of the Atmosphere Solar Radiation:
Fits to a black body between 5500 K and 6000 K.

3. Top of the Atmosphere Solar Radiation:

4. SOLAR SPECTRUM:
TOP OF THE ATMOSPHERE

5. SOLAR SPECTRUM:
TOP OF THE ATMOSPHERE AND AT THE SURFACE

6. SOLAR SPECTRUM:
Effects of Rayleigh (gas) scattering, O2 and N2.

7. SOLAR SPECTRUM:
Effects of Rayleigh (gas) scattering, O2 and N2,
And effects of extinction by aerosol particles.

8. SOLAR SPECTRUM:
Effects of gaseous absorption.

9. Sun and Earth Spectra and Atmospheric Windows
Visible Window
IR Dirty Window
Absorption only, not effects of Rayleigh Scattering by gases.

10. Rayleigh Scattering In Perspective Relative to Absorption

11. Absorption cross sections of O3 and O2 in the UV and Visible.
Strongly affects atmospheric chemistry, thermal structure, and amount of deadly UV that doesn’t make it to the surface.

12. Rayleigh Scattering (light scattering by air as dipole radiation)

13. Atmospheric Temperature Profile: US “Standard” Atmosphere.
Cirrus cloud level.
High cold clouds, visible optical depth range
0.001 to 10, emits IR to surface in the IR window.
From Liou

14. Solar Spectrum, Top of the Atmosphere and at the Surface
Shaded region is solar irradiance removed by Rayleigh scattering and absorption by gases as indicated. (from Liou).

15. Electronic, Vibrational, energy levels and the big break up (dissociation level)
From Liou