Definitions

The albedo is the ratio of the radiation of radiation reflect by an object to the energy incident upon it.

The atmospheric emissivity is the ratio of the radiant energy emitted per unit time per unit area by the atmosphere to the energy emitted by an ideal blackbody at the same temperature.

Earth Radiation Budget Experiment is a NASA sponsored research program to measure Earth's radiation budget using a series of satellites.

Energy balance requires that the absorbed solar energy equals the infrared radiation emitted to space.

Solar Constant is the average rate of solar energy received on a surface perpendicular to the incident radiation at an average distance from the sun. The solar constant of Earth is approximately 1367 Wm^-2.