TY - JOUR
T1 - Observations of the auroral width spectrum at kilometre-scale size
AU - Partamies, N.
AU - Syrjäsuo, M.
AU - Donovan, E.
AU - Connors, M.
AU - Charrois, D.
AU - Knudsen, D.
AU - Kryzanowsky, Z.
PY - 2010
Y1 - 2010
N2 - 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.
AB - 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.
KW - Instruments and techniques) - Magnetospheric physics (Auroral phenomena)
KW - Ionosphere (Auroral ionosphere
UR - http://www.scopus.com/inward/record.url?scp=77949347636&partnerID=8YFLogxK
U2 - 10.5194/angeo-28-711-2010
DO - 10.5194/angeo-28-711-2010
M3 - Journal Article
AN - SCOPUS:77949347636
SN - 0992-7689
VL - 28
SP - 711
EP - 718
JO - Annales Geophysicae
JF - Annales Geophysicae
IS - 3
ER -