from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The average density of solar radiation measured outside Earth's atmosphere and at Earth's mean distance from the sun, equal to 0.140 watt per square centimeter.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The amount of incoming solar radiation per unit area, measured on the outer surface of Earth's atmosphere, in a plane perpendicular to the rays.
from the GNU version of the Collaborative International Dictionary of English
- n. the quantity of heat received by the earth from the sun in a unit of time. It is, on the C. G. S. system, 0.0417 small calories per square centimeter per second.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the rate at which radiant solar energy is received at the outer layer of the earth's atmosphere
Sorry, no etymologies found.