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Credit & Copyright: Sigurdur H. Stefnisson
Explanation:
Aurorae usually occur high above the clouds.
The auroral glow is created when fast-moving
particles ejected from the
Sun impact air molecules high in the
Earth's atmosphere.
An
oxygen molecule, for example,
will glow in a green light when reacquiring an
electron
lost during a collision with a solar particle.
The lowest part of an
aurora will typically occur at 100 kilometers up, while
most clouds usually exist only below about 10 kilometers.
The relative heights of clouds and aurorae are shown clearly in the
above picture from
Iceland, where aurorae are relatively common.
Over the past weekend, one of the
largest sunspot groups ever recorded has been
associated with
explosive solar activity
and expansive terrestrial aurora displays.
Although in Earth's northern hemisphere
aurorae are usually seen only in the far north,
these aurorae
were so prevalent they were
imaged by a
continuous nighttime camera
operating in southern
Arizona!
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: aurora - clouds - iceland
Publications with words: aurora - clouds - iceland
See also:
- APOD: 2024 January 14 Á Dragon Aurora over Iceland
- APOD: 2024 January 3 Á A SAR Arc from New Zealand
- APOD: 2023 December 12 Á Aurora and Milky Way over Norway
- The SAR and the Milky Way
- APOD: 2023 November 5 Á Creature Aurora Over Norway
- APOD: 2023 October 22 Á Ghost Aurora over Canada
- APOD: 2023 August 20 Á A Roll Cloud Over Wisconsin