Jan 29, 2010

Solar Spectrum, Variability, and Atmospheric Absorption





Above: This image, courtesy of Dr. Judith Lean at the US Naval Research Laboratory, shows the spectrum of solar radiation from 10 to 100,000 nm (dark blue), its variability betwen Solar Maximum and Solar Minimum (green) and the relative transparency of Earth's atmosphere at sea level (light blue). At wavelengths shorter than about 300 nm, there is a relatively large variation in the Sun's extreme UV and x-ray output (greater than 1%), but the Earth's atmosphere is nearly opaque at those wavelengths. For Earth-dwelling beach-goers there is no significant difference between Solar Max and solar minimum.