Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 28, 711-718, 2010
https://doi.org/10.5194/angeo-28-711-2010
© Author(s) 2010. This work is distributed under
the Creative Commons Attribution 3.0 License.
 
09 Mar 2010
Observations of the auroral width spectrum at kilometre-scale size
N. Partamies1, M. Syrjäsuo1, E. Donovan2, M. Connors3, D. Charrois4, D. Knudsen2, and Z. Kryzanowsky2 1Finnish Meteorological Institute, Helsinki, Finland
2Institute of Space Research, University of Calgary, Calgary, Alberta, Canada
3Athabasca University, Athabasca, Alberta, Canada
4Syzygy Research & Technology, Legal, Alberta, Canada
Abstract. 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.

Citation: Partamies, N., Syrjäsuo, M., Donovan, E., Connors, M., Charrois, D., Knudsen, D., and Kryzanowsky, Z.: Observations of the auroral width spectrum at kilometre-scale size, Ann. Geophys., 28, 711-718, https://doi.org/10.5194/angeo-28-711-2010, 2010.
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