ALBEDO:

The fraction of incoming long-wave solar radiation that is reflected off of high clouds, ice and snow. The earth's polar regions, especially the Antarctic ice sheet, have high albedos. Expressed as a fraction of light reflected values range from zero (no reflection) to one (total reflection).

ABSORPTION:

Electromagnetic radiation is absorbed in passing through certain gases and fluids and by solids. The absorption spectrum of each substance is unique, and certain wavelengths of light are absorbed more strongly than others in the process. Carbon dioxide, water vapor, and methane are gases that effectively absorb infrared radiation, but not ultravioled radiation.

VISIBLE LIGHT AND THE ELECTROMAGNETIC SPECTRUM

Electromagnetic waves or radiation is characterized by its wavelength. Wavelengths of the spectrum vary from very short, invisible radiation such as gamma rays, x-rays, and ultravioled light to long wavelengths found in infrared, radar, and radio waves. The visible portion of the spectrum ranges over a narrow range of wavelengths (principally 400 to 700 nannometers) and lies between the ultraviolet and infrared porttions of the spectrum.

A MNEMONIC DEVICE

ROY G. BIV (red, orange, yellow, green, blue, indigo, violet) is a useful device for remembering the colors of the visible spectrum. Red is the long wave length and violet is the short wavelength.