Editing Sunset (section)

==Colors==
{{See also|Sunrise#Colors}}
{{Further|Atmospheric optics}}
[[File:Majestic Twilight.jpg|thumb|upright|Evening [[twilight]] in [[Joshua Tree, California]], displaying the separation of yellow colors in the direction from the Sun below the [[horizon]] to the observer, and the blue components scattered from the surrounding sky]]

As a ray of white sunlight travels through the atmosphere to an observer, some of the colors are scattered out of the beam by air molecules and [[Atmospheric particulate matter|airborne particles]], changing the final color of the beam the viewer sees.
Because the shorter [[wavelength]] components, such as blue and green, scatter more strongly, these colors are preferentially removed from the beam.<ref name="saha">{{cite book |author=K. Saha |title=The Earth's Atmosphere – Its Physics and Dynamics |url=https://archive.org/details/earthsatmosphere00saha_371 |url-access=limited |date=2008 |publisher=Springer |isbn=978-3-540-78426-5 |page=[https://archive.org/details/earthsatmosphere00saha_371/page/n124 107]}}</ref> At sunrise and sunset, when the path through the atmosphere is longer, the blue and green components are removed almost completely, leaving the longer wavelength orange and red [[hue]]s we see at those times. The remaining reddened sunlight can then be scattered by cloud droplets and other relatively large particles to light up the horizon red and orange.<ref name="guenther">{{cite book |editor=B. Guenther |title=Encyclopedia of Modern Optics |publisher=[[Elsevier]] |date=2005 |volume=1 |page=186}}</ref> The removal of the shorter wavelengths of light is due to [[Rayleigh scattering]] by air molecules and particles much smaller than the wavelength of visible light (less than 50&nbsp;nm in diameter).<ref>{{cite web|url=http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html |title=Hyperphysics, Georgia State University |publisher=Hyperphysics.phy-astr.gsu.edu |access-date=2012-04-07}}</ref><ref name="Bohren">Craig Bohren (ed.), ''Selected Papers on Scattering in the Atmosphere'', SPIE Optical Engineering Press, Bellingham, WA, 1989</ref>  The scattering by cloud droplets and other particles with diameters comparable to or larger than the sunlight's wavelengths (> 600&nbsp;nm) is due to [[Mie theory|Mie scattering]] and is not strongly wavelength-dependent.  Mie scattering is responsible for the light scattered by clouds, and also for the daytime halo of white light around the Sun (forward scattering of white light).<ref>{{cite web|url=http://www.spc.noaa.gov/publications/corfidi/sunset.html|title=The Science of Sunsets|first=Stephen F.|last=Corfidi|publisher = NOAA/NWS Storm Prediction Center|location = Norman, OK |date=October 2024}}</ref><ref>{{cite web|url=http://www.nasa.gov/centers/langley/news/factsheets/Aerosols.html|date=August 1996|title=Atmospheric Aerosols: What Are They, and Why Are They So Important?|publisher=nasa.gov}}</ref><ref name="hecht">{{cite book |author=E. Hecht |title=Optics |url=https://archive.org/details/optics00ehec |url-access=limited |edition=4th |date=2002 |publisher=Addison Wesley |isbn=0-321-18878-0 |page=[https://archive.org/details/optics00ehec/page/n94 88]}}</ref>

Sunset colors are typically more brilliant than sunrise colors, because the evening air contains more particles than morning air.<ref name="saha" /><ref name="guenther" /><ref name="Bohren" /><ref name="hecht" /> Sometimes just before sunrise or after sunset a [[green flash]] can be seen.<ref>{{cite web|url=http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/redsun.html|title=Red Sunset, Green Flash}}</ref>

Ash from volcanic eruptions, trapped within the [[troposphere]], tends to mute sunset and sunrise colors, while volcanic ejecta that is instead lofted into the [[stratosphere]] (as thin clouds of tiny sulfuric acid droplets), can yield beautiful post-sunset colors called [[afterglow]]s and pre-sunrise glows. A number of eruptions, including those of [[1991 eruption of Mount Pinatubo|Mount Pinatubo in 1991]] and [[1883 eruption of Krakatoa|Krakatoa in 1883]], have produced sufficiently high [[stratus clouds]] containing [[sulfuric acid]] to yield remarkable sunset afterglows (and pre-sunrise glows) around the world. The high-altitude clouds serve to reflect strongly reddened sunlight still striking the stratosphere after sunset, down to the surface.

Some of the most varied colors at sunset can be found in the opposite or eastern sky after the [[Sun]] has set during twilight. Depending on weather conditions and the types of [[cloud]]s present, these colors have a wide spectrum, and can produce unusual results.{{citation needed|date=October 2021}}