Alpenglow (from German: Alpenglühen, lit. 'Alps glow'; Italian: enrosadira) is an optical phenomenon that appears as a horizontal reddish glow near the horizon opposite to the Sun when the solar disk is just below the horizon.[1]
Alpenglow on Mt. Forbes in the Canadian RockiesAlpenglow at dawn, with the stars still visible. Maroon Bells and Maroon Lake, Colorado, United StatesSolar ray 1 is the lowest from the Sun – the Sun is set. Solar ray 2 is reflected in the (snow) clouds to the observer.
Strictly speaking, alpenglow refers to indirect sunlightreflected or diffracted by the atmosphere after sunset or before sunrise. This diffuse illumination creates soft shadows in addition to the reddish color. The term is also used informally to include direct illumination by the reddish light of the rising or setting sun, with sharply defined shadows.
Reflected sunlightedit
When the Sun is below the horizon, sunlight has no direct path to reach a mountain. Unlike the direct sunlight around sunrise or sunset, the light that causes alpenglow is reflected off airborne precipitation, ice crystals, or particulates in the lower atmosphere. These conditions differentiate between direct sunlight around sunrise or sunset and alpenglow.[2]
The term is generally confused to be any sunrise or sunset light reflected off the mountains or clouds, but alpenglow in the strict sense of the word is not direct sunlight and is only visible after sunset or before sunrise.[1]
After sunset, if mountains are absent, aerosols in the eastern sky can be illuminated in a similar way by the remaining scattered reddish light above the fringe of Earth's shadow. This backscattered light produces a pinkish band opposite of the Sun's direction, called the Belt of Venus.[3]
Direct sunlightedit
Alpenglow in a looser sense may refer to any illumination by the rosy or reddish light of the setting or rising Sun.[4][5]
^ abLynch, David K.; Livingston, William (June 2001). Color and Light in Nature. Cambridge University Press. p. 41. ISBN9780521775045.
^Cushman, Ruth Carol; Jones, Stephen (December 28, 2009). . Archived from the original on 2018-01-10. Retrieved 2018-01-10.
^Powell, Jonathan (2018). "Atmospheric Factors and Features". The Patrick Moore Practical Astronomy Series. Cham: Springer International Publishing. pp. 105–130. doi:10.1007/978-3-319-97701-0_8. ISBN978-3-319-97700-3. ISSN 1431-9756.
^"What Is Alpenglow?". Digital Photography School. 2012-11-01. Retrieved 2018-01-10.
alpenglow, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, january, 2018, l. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Alpenglow news newspapers books scholar JSTOR January 2018 Learn how and when to remove this template message Alpenglow from German Alpengluhen lit Alps glow Italian enrosadira is an optical phenomenon that appears as a horizontal reddish glow near the horizon opposite to the Sun when the solar disk is just below the horizon 1 Alpenglow on Mt Forbes in the Canadian RockiesAlpenglow at dawn with the stars still visible Maroon Bells and Maroon Lake Colorado United StatesSolar ray 1 is the lowest from the Sun the Sun is set Solar ray 2 is reflected in the snow clouds to the observer Contents 1 Description 1 1 Reflected sunlight 1 2 Direct sunlight 2 See also 3 ReferencesDescription editStrictly speaking alpenglow refers to indirect sunlight reflected or diffracted by the atmosphere after sunset or before sunrise This diffuse illumination creates soft shadows in addition to the reddish color The term is also used informally to include direct illumination by the reddish light of the rising or setting sun with sharply defined shadows Reflected sunlight edit When the Sun is below the horizon sunlight has no direct path to reach a mountain Unlike the direct sunlight around sunrise or sunset the light that causes alpenglow is reflected off airborne precipitation ice crystals or particulates in the lower atmosphere These conditions differentiate between direct sunlight around sunrise or sunset and alpenglow 2 The term is generally confused to be any sunrise or sunset light reflected off the mountains or clouds but alpenglow in the strict sense of the word is not direct sunlight and is only visible after sunset or before sunrise 1 After sunset if mountains are absent aerosols in the eastern sky can be illuminated in a similar way by the remaining scattered reddish light above the fringe of Earth s shadow This backscattered light produces a pinkish band opposite of the Sun s direction called the Belt of Venus 3 Direct sunlight edit Alpenglow in a looser sense may refer to any illumination by the rosy or reddish light of the setting or rising Sun 4 5 See also editGolden hour photography Belt of VenusReferences edit nbsp Wikimedia Commons has media related to Alpenglow a b Lynch David K Livingston William June 2001 Color and Light in Nature Cambridge University Press p 41 ISBN 9780521775045 Cushman Ruth Carol Jones Stephen December 28 2009 Catch Boulder s alpenglow blushing mountains this winter Archived from the original on 2018 01 10 Retrieved 2018 01 10 Powell Jonathan 2018 Atmospheric Factors and Features The Patrick Moore Practical Astronomy Series Cham Springer International Publishing pp 105 130 doi 10 1007 978 3 319 97701 0 8 ISBN 978 3 319 97700 3 ISSN 1431 9756 What Is Alpenglow Digital Photography School 2012 11 01 Retrieved 2018 01 10 alpenglow Lexico UK English Dictionary Oxford University Press Archived from the original on 2021 09 05 nbsp This article about atmospheric science is a stub You can help Wikipedia by expanding it vte nbsp This optics related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Alpenglow amp oldid 1189252233, wikipedia, wiki, book, books, library,
