Alpenglow


Alpenglow

Alpenglow (from German: "Alpenglühen") is an optical phenomenon. When the Sun is just below the horizon, a horizontal red glowing band can sometimes be observed on the opposite horizon. Alpenglow is easiest to observe when mountains are illuminated but can also be observed when the sky is illuminated through backscattering.

Since the Sun is below the horizon, there is no direct path for the light to reach the mountain. Instead, light reflects off airborne snow, water, or ice particles low in the atmosphere. It is this circumstance that separates a normal sunrise or sunset from alpenglow.

Although the term may be loosely applied to any sunrise or sunset light seen on the mountains, true alpenglow is not direct sunlight and is only observed after sunset or before sunrise.

In the absence of mountains, the aerosols in the eastern portion of the sky themselves can still be illuminated in the same way by the remaining red scattered light straddling the border of the Earth's own shadow (the terminator). This back-scattered light produces a red band opposite the Sun.

ee also

* Golden hour (photography)


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Alpenglow — Al pen*glow , n. A reddish glow seen near sunset or sunrise on the summits of mountains; specif., a reillumination sometimes observed after the summits have passed into shadow, supposed to be due to a curving downward (refraction) of the light… …   The Collaborative International Dictionary of English

  • alpenglow — [al′pən glō΄] n. [partial transl. of Ger alpenglühen < alpen, of the Alps + glühen, GLOW] a reddish glow seen on mountain tops before sunrise or after sunset …   English World dictionary

  • alpenglow — noun Etymology: part translation of German Alpenglühen, from Alpen Alps + Glühen glow Date: 1871 a reddish glow seen near sunset or sunrise on the summits of mountains …   New Collegiate Dictionary

  • alpenglow — /al peuhn gloh /, n. a reddish glow often seen on the summits of mountains just before sunrise or just after sunset. [1870 75; < G Alpenglühen, with GLOW r. G glühen] * * * …   Universalium

  • alpenglow — noun A rosy or reddish glow seen near sunset or sunrise on the summits of mountains, especially snow covered mountains …   Wiktionary

  • alpenglow — al·pen·glow || ælpÉ™ngləʊ n. reddish glow seen on mountaintops before sunrise or after sunset …   English contemporary dictionary

  • alpenglow — [ alpəngləʊ] noun the rosy light of the setting or rising sun seen on high mountains. Origin C19: a partial translation of Ger. Alpenglühen, lit. Alp glow …   English new terms dictionary

  • alpenglow — al·pen·glow …   English syllables

  • alpenglow — al•pen•glow [[t]ˈæl pənˌgloʊ[/t]] n. mer a reddish glow often seen on the summits of mountains just before sunrise or just after sunset • Etymology: 1870–75; < G Alpenglühen, =Alpen Alps with glow r. G Glühen …   From formal English to slang

  • alpenglow — /ˈælpəngloʊ/ (say alpuhngloh) noun a reddish glow often seen on the summits of snow covered mountains before sunrise and after sunset. {translation of German Alpenglühen} …   Australian English dictionary