Ground-based and satellite observations of high-latitude auroral activity in the dusk sector of the auroral oval

Kauristie, K., Pulkkinen, T. I., Amm, O., Viljanen, A., Syrjäsuo, M., Janhunen, P., Massetti, S., Orsini, S., Candidi, M., Watermann, J., Donovan, E., Prikryl, P., Mann, I. R., Eglitis, P., Smith, C., Denig, W. F., Opgenoorth, H. J., Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172, Dunlop, M., Vaivads, A. and André, M. (2001) Ground-based and satellite observations of high-latitude auroral activity in the dusk sector of the auroral oval. Annales Geophysicae, 19 (10/12). pp. 1683-1696. ISSN 0992-7689 doi: 10.5194/angeo-19-1683-2001

Abstract/Summary

On 7 December 2000, during 13:30-15:30 UT the MIRACLE all-sky camera at Ny Alesund observed auroras at high-latitudes (MLAT similar to 76) simultaneously when the Cluster spacecraft were skimming the magnetopause in the same MLT sector (at similar to 16:00-18:00 MLT). The location of the auroras (near the ionospheric convection reversal boundary) and the clear correlation between their dynamics and IMF variations suggests their close relationship with R1 currents. Consequently, we can assume that the Cluster spacecraft were making observations in the magnetospheric region associated with the auroras, although exact magnetic conjugacy between the ground-based and satellite observations did not exist. The solar wind variations appeared to control both the behaviour of the auroras and the magnetopause dynamics. Auroral structures were observed at Ny Alesund especially during periods of negative IMF B-Z. In addition, the Cluster spacecraft experienced periodic (T similar to 4 - 6 min) encounters between magnetospheric and magnetosheath plasmas. These undulations of the boundary can be interpreted as a consequence of tailward propagating magnetopause surface waves. Simultaneous dusk sector ground-based observations show weak, but discernible magnetic pulsations (Pc 5) and occasionally periodic variations (T - 2 - 3 min) in the high-latitude auroras. In the dusk sector, Pc 5 activity was stronger and had characteristics that were consistent with a field line resonance type of activity. When IMF BZ stayed positive for a longer period, the auroras were dimmer and the spacecraft stayed at the outer edge of the magnetopause where they observed electromagnetic pulsations with T similar to 1 min. We find these observations interesting especially from the viewpoint of previously presented studies relating poleward-moving high-latitude auroras with pulsation activity and MHD waves propagating at the magnetospheric boundary layers.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38714
Identification Number/DOI	10.5194/angeo-19-1683-2001
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Copernicus Publications
Download/View statistics	View download statistics for this item