Solar Radiation Spectrum.pptx

Elaboration of solar spectrum

1. Solar radiation spectrum The sun produces light with wavelengths in the range of about 200 nm to 2600 nm. It is similar to a 5525 K (5250 °C) blackbody, which is approximately the temperature at the surface of the sun. Wavelength of ultraviolet (UV) rays ranges from 200 to 400 nm, visible light: 400 nm (violet) to 700 nm (red) and the infrared (IR): 700 nm to 1mm. As light passes through the atmosphere, some is absorbed by gases with specific absorption bands. Ozone molecules absorbs almost completely the short wave radiation below 0.29 µm. Thus the shortest wavelength that reaches the Earth’s surface is approximately 0.29 µm. Water vapour absorbs mainly the IR bands. Maximum intensity occurs at wavelength of 480 nm. Radiation having wavelength ranging from 0 to 380 nm, 380 to 780 nm and 780 to 4000 nm contains 7, 47.3 and 45.7 % of total energy in the radiation. Solar spectrum 1