Solar Radiation on Earth
Name: Joseph J. Schottler
Date: 1999 - 2000
What is the maximum radiated power per unit area that the
sun can deliver to the surface of the earth.
The amount of energy that the sun gives to the earth is about 1370 watts per
meter squared. This energy comes in all the wavelengths that the sun puts out
(mostly visible light, but some UV, some "heat-like" infrared. Not all of this
energy is absorbed by the planet. Some hits the tops of while clouds (for
example) and is reflected right back to space. The average power hitting the
surface of the earth varies with location and climate, but is about 1000 watts
per meter squared. Its better is Phoenix, less in Seattle. A good source for
this type information is under solar heating.
A good source for how much the question you asked is NASA. NASA launched an
instrument to measure this number you ask about. It is the solar irradiance,
or solar constant. The instrument's name was ACRIM.
I found alot about ACRIM at www.nasa.gov/search/
enter words or phrases, put in
acrim, hit the search button read the acrim summary, its technical tho.
skip down to the Total Solar Irradiance entry, and go to this web address.It
puts up a graph, which is where I got the number I told you.
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Update: June 2012