 |
| Titel |
Using spectral characteristics to interpret auroral imaging in the 731.9 nm O+ line |
| VerfasserIn |
H. Dahlgren, N. Ivchenko, B. S. Lanchester, J. Sullivan, D. Whiter, G. Marklund, A. Strømme |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 26, no. 7 ; Nr. 26, no. 7 (2008-07-15), S.1905-1917 |
| Datensatznummer |
250016156
|
| Publikation (Nr.) |
 copernicus.org/angeo-26-1905-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| Simultaneous observations were made of dynamic aurora during
substorm activity on 26 January 2006 with three high spatial and
temporal resolution instruments: the ASK (Auroral Structure and
Kinetics) instrument, SIF (Spectrographic Imaging Facility) and
ESR (EISCAT Svalbard Radar), all located on Svalbard
(78° N, 16.2° E). One of the narrow field of view
ASK cameras is designed to detect O+ ion emission at 731.9 nm.
From the spectrographic data we have been able to determine
the amount of contaminating N2 and OH emission
detected in the same filter. This is of great importance to
further studies using the ASK instrument, when the O+ ion
emission will be used to detect flows and afterglows in active
aurora. The ratio of O+ to N2 emission is dependent on
the energy spectra of electron precipitation, and was found
to be related to changes in the morphology of the
small-scale aurora. The ESR measured height profiles of electron
densities, which allowed estimates to be made of the energy
spectrum of the precipitation during the events studied with
optical data from ASK and SIF. It was found that the higher energy
precipitation corresponded to discrete and dynamic features,
including curls, and low energy precipitation corresponded to
auroral signatures that were dominated by rays. The evolution
of these changes on time scales of seconds is of importance to
theories of auroral acceleration mechanisms. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|