Shortwave radiation


Shortwave radiation is radiant energy with wavelengths in the visible, near-ultraviolet, and near-infrared spectra.
There is no standard cut-off for the near-infrared range; therefore, the shortwave radiation range is also variously defined. It may be broadly defined to include all radiation with a wavelength of 0.1μm and 5.0μm or narrowly defined so as to include only radiation between 0.2μm and 3.0μm.
There is little radiation flux to the Earth's surface below 0.2μm or above 3.0μm, although photon flux remains significant as far as 6.0μm, compared to shorter wavelength fluxes. UV-C radiation spans from 0.1μm to.28μm, UV-B from 0.28μm to 0.315μm, UV-A from 0.315μm to 0.4μm, the visible spectrum from 0.4μm to 0.7μm, and NIR arguably from 0.7μm to 5.0μm, beyond which the infrared is thermal.
Shortwave radiation is distinguished from longwave radiation. Downward shortwave radiation is sensitive to solar zenith angle, cloud cover.