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Ann. Geophys., 26, 1041-1048, 2008
www.ann-geophys.net/26/1041/2008/
© European Geosciences Union 2008
Morphology and dynamics of aurora at fine scale: first results from the ASK instrument
H. Dahlgren1, N. Ivchenko1, J. Sullivan2, B. S. Lanchester2, G. Marklund1, and D. Whiter2
1Space and Plasma Physics, School of electrical engineering, KTH, Stockholm, Sweden
2School of Physics and Astronomy, University of Southampton, UK
Abstract. The ASK instrument (Auroral Structure and Kinetics) is a narrow
field auroral imager, providing simultaneous images of
aurora in three different spectral bands at multiple frames per
second resolution. The three emission species studied are
O2+ (5620 Å), O+ (7319 Å) and
O (7774 Å). ASK was installed and operated for
the first time in an observational campaign on Svalbard, from
December 2005 to March 2006. The measurements were supported by
data from the Spectrographic Imaging Facility (SIF). The relation
between the morphology and dynamics of the visible aurora and its
spectral characteristics is studied for selected events from this
period. In these events it is found that dynamic aurora is coupled
to high energy electron precipitation. By studying the
O2+/O intensity ratio we find that some auroral
filaments are caused by higher energy precipitation within regions
of lower energy precipitation, whereas other filaments are the
result of a higher particle flux compared to the surroundings.
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