Pulsating Aurora over Iceland
Explanation:
Why do some auroras pulsate?
No one is sure.
Although this unusual behavior has been known for a long time,
the cause remains an active topic of research.
Featured here is a dramatic video that captured some impressive pulsating auroras
in mid-March over
SvМnafellsjЖkull Glacier
in
Iceland.
The 48-second video is shown is not time-lapse.
The real-time pulsations are
exemplified by sequences where the astrophotographer is visible moving about
in the foreground.
A close inspection of the enigmatic flickering
sky colors
reveals that some structures appear to repeat, while others do not.
The quick rapidity of the pulsations seen here is somewhat unusual -- more common
are
aurora with pulsations that last
several seconds.
Recent research shows that pulsations are more common in electron-generated
aurora,
rather than
proton aurora, and that the
Earth's local magnetic field
may
fluctuate in unison.
Astrophysicists:
Browse 1,000+ codes in the Astrophysics Source Code Library
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.