Observations of the auroral width spectrum at kilometre-scale size
This study examines auroral colour camera data from the Canadian Dense Array Imaging SYstem (DAISY). The Dense Array consists of three imagers with different narrow (compared to all-sky view) field-of-view optics. The main scientific motivation arises from an earlier study by Knudsen et al. (2001...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2010-03-01
|
| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/28/711/2010/angeo-28-711-2010.pdf |
| Summary: | This study examines auroral colour camera data from the Canadian Dense Array
Imaging SYstem (DAISY). The Dense Array consists of three imagers with
different narrow (compared to all-sky view) field-of-view optics. The main
scientific motivation arises from an earlier study by Knudsen et al. (2001) who
used All-Sky Imager (ASI) combined with even earlier TV camera observations
(Maggs and Davis, 1968) to suggest that there is a gap in the distribution of auroral
arc widths at around 1 km. With DAISY observations we are able to show that
the gap is an instrument artifact and due to limited spatial resolution and
coverage of commonly used instrumentation, namely ASIs and TV cameras. If the
auroral scale size spectrum is indeed continuous, the mechanisms forming
these structures should be able to produce all of the different scale sizes.
So far, such a single process has not been proposed in the literature and
very few models are designed to interact with each other even though the
range of their favourable conditions do overlap. All scale-sizes should be
considered in the future studies of auroral forms and electron acceleration
regions, both in observational and theoretical approaches. |
|---|---|
| ISSN: | 0992-7689 1432-0576 |