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| Titel |
Observation of O+ (4P-4D0) lines in electron aurora over Svalbard |
| VerfasserIn |
N. Ivchenko, M. H. Rees, B. S. Lanchester, D. Lummerzheim, M. Galand, K. Throp, I. Furniss |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 22, no. 8 ; Nr. 22, no. 8 (2004-09-07), S.2805-2817 |
| Datensatznummer |
250014967
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| Publikation (Nr.) |
 copernicus.org/angeo-22-2805-2004.pdf |
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| Zusammenfassung |
| This work reports on observations of O+ lines in aurora over
Svalbard, Norway. The Spectrographic Imaging Facility measures auroral
spectra in three wavelength intervals
(Hβ, N+2 1N(0,2) and N+2 1N(1,3)).
The oxygen ion multiplet (4639-4696Å) is blended
with the band.
It is found that in electron aurora, the brightness
of this multiplet, is
on average, about 0.1 of the total brightness.
A joint optical and incoherent scatter radar study of an
electron aurora event shows that the ratio is enhanced
when the ionisation in the upper E-layer (140-190km)
is significant with respect to the E-layer peak
below 130km. Rayed arcs were observed on one such
occasion, whereas on other occasions the auroral
intensity was below the threshold of the imager.
A one-dimensional electron transport model is used to
estimate the cross section for production of the multiplet
in electron collisions, yielding 0.18x10-18cm2. |
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