Monoenergetic high-energy electron precipitation in thin auroral filaments
Article first published online: 19 OCT 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 20, 28 October 2012
How to Cite
2012), Monoenergetic high-energy electron precipitation in thin auroral filaments, Geophys. Res. Lett., 39, L20101, doi:10.1029/2012GL053466., , and (
- Issue published online: 19 OCT 2012
- Article first published online: 19 OCT 2012
- Manuscript Revised: 17 SEP 2012
- Manuscript Accepted: 17 SEP 2012
- Manuscript Received: 6 AUG 2012
- fine scale structure;
- monoenergetic precipitation;
- multispectral observations
 The energy distribution of the electron precipitation responsible for extremely narrow (70 m) and dynamic auroral filaments is found to be sharply peaked at around 8 keV. The events were captured with high resolution low-light optical imagers located near Tromsø, Norway. The method uses imaging in two emissions which have different energy dependent responses to auroral electron precipitation. The key feature of the events was that no difference in the altitude of the two emissions was detected, nor any time-of-flight dispersion, thus leading to the conclusion that the filaments were caused by monoenergetic precipitation. Comparisons with an electron transport and ion chemistry model show that the high energy filaments were embedded in a region of lower energy precipitation of about 4 keV. There is currently no consistent theory to explain the characteristics of the observed auroral structures.