Average Distribution of Incoming Solar Radiation

Mechanisms of heat transfer
Radiation (electromagnetic radiation)
Governed by basic laws  
All objects, at whatever temperature, emit radiation
Hotter objects radiate more total energy per unit area than do cooler objects
The hotter the radiating body, the shorter the wavelength of maximum radiation
Objects that are good absorbers of radiation are good emitters as well  

Incoming solar radiation
Atmosphere is largely transparent to incoming solar radiation
Atmospheric effects
Reflection – albedo (percent reflected)
Scattering
Absorption  
Most visible radiation reaches the surface
About 50 percent absorbed at Earth’s surface