GEOG 1001 Lecture Notes - Lecture 5: Rayleigh Scattering, Solar Irradiance, Shortwave Radio
Document Summary
The sun emits about . 5 micro meters/ k of visible light. The visible light spectrum is between about . 4 micro meters/ k and . 7 micro meters/ k. Earth emits about 10 micro meters/ k at a maximum. The sun radiates short waves while the earth radiates long waves. Energy is not created or destroyed, but changes form (the first law of thermodynamics). All radiation received at earth"s surface is both direct and indirect. Solar constant : the average amount of energy received at the outer edges of the atmosphere, is equal to 1372 w/m2. Scattering : changing direction of energy movements, without altering its wavelength (7% of. Earth"s reflectivity): only about 7% of energy is scattered. Refraction : the change in the speed and direction of light. Reflection : energy bounces directly back out to space. Absorption : assimilation of energy by material and conversion to a different wavelength.
