Editing Shortwave radiation (optics)

{{Short description|Type of radiant energy}}
{{redirect|Shortwave radiation|radio frequency radiation|Shortwave band|other uses|Shortwave (disambiguation)}}
[[File:Sun-Earth Logarithmic Spectrums with Accurate Scaling.svg|thumb|Spectral intensity of sunlight (average at top of atmosphere) and thermal radiation emitted by Earth's surface.]]

'''Shortwave radiation''' (SW) is [[thermal radiation]] in the [[optical spectrum]], including [[visible radiation|visible]] (VIS), near-[[ultraviolet radiation|ultraviolet]] (UV), and [[near-infrared]] (NIR) 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 0.1[[micrometre|μm]] and 5.0μm or narrowly defined so as to include only radiation between 0.2μm and 3.0μm.

There is little radiation flux (in terms of [[Irradiance|W/m<sup>2</sup>]]) 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 [[near-infrared|NIR]] arguably from 0.7μm to 5.0μm, beyond which the infrared is thermal.<ref>However, the definition of thermal infrared may start at wavelengths as short as 1.1μm (longer than which optical instruments have difficulty measuring) or anywhere between 2.0μm and 4.0μm, depending on the method of measurement and its purpose.</ref>

Shortwave radiation is distinguished from [[outgoing longwave radiation|''longwave radiation'']]. '''Downward shortwave radiation''' is related to [[solar irradiance]] and is sensitive to [[solar zenith angle]] and [[cloud cover]].<ref>[https://dx.doi.org/10.1016/j.rse.2012.04.006 L. Chen, G. Yan, T. Wang, H. Ren, J. Calbó, J. Zhao, R. McKenzie (2012), Estimation of surface shortwave radiation components under all sky conditions: Modeling and sensitivity analysis, Remote Sensing of Environment, 123: 457–469.]</ref>

==See also ==
* [[Outgoing longwave radiation]]

==Notes==
{{Reflist}}

==External links==
* [https://web.archive.org/web/20050420085336/http://www.nsdl.arm.gov/Library/glossary.shtml#Shortwave_radiation National Science Digital Library - Shortwave radiation]
* [https://web.archive.org/web/20040213233926/http://avc.comm.nsdlib.org/cgi-bin/wiki_grade_interface.pl?Measuring_Solar_Radiation ''Measuring Solar Radiation: The Solar Infrared Radiation Station (SIRS)'']. A lesson plan that deals with shortwave radiation from the SIRS instrument.

==References==
*Zhang, Y., W. B. Rossow, A. A. Lacis, V. Oinas and M. I. Mischenko (2004). "Calculation of radiative fluxes from the surface to the top of atmosphere based on [[International Satellite Cloud Climatology Project|ISCCP]] and other global data sets:  Refinements of the radiative transfer model and the input data." Journal of Geophysical Research-Atmospheres 109(D19105).<!--what does this site have to do with text above?-->
*[https://dx.doi.org/10.1016/j.rse.2012.04.006 L. Chen, G. Yan, T. Wang, H. Ren, J. Calbó, J. Zhao, R. McKenzie (2012), Estimation of surface shortwave radiation components under all sky conditions: Modeling and sensitivity analysis, Remote Sensing of Environment, 123: 457–469.]

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[[Category:Waves]]


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