Abstract
Observations of electron and proton precipitation fluxes and Birkeland currents from spacecraft DMSP F7 and simultaneous ground-based optical measurements from Svalbard (~75° geom.lat.) of dayside aurorae (~ 09 MLT) are presented. In these cases, the auroral emissions within the field of view can be separated in different latitudinal zones with corresponding structures in the particle precipitation. The temporal evolution of these structures is monitored by the ground-based instruments, indicating the presence of both stationary cleft emissions produced by soft electron fluxes (energy few hundred eV) and multiple, discrete arcs and arc-fragments corresponding to the precipitation of keV electrons. The latter are associated with narrow sheets of upward flowing Birkeland currents and reduced proton precipitation, suggesting the presence of field-aligned potential drops above the spacecraft. Field-aligned current systems separated in latitude and associated with plasma-sheet-like and LLBL-like particles, respectively, are observed during the satellite pass presented here, which occurred after a sharp IMF Bz polarity change.
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© 1989 Kluwer Academic Publishers
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Sandholt, P.E. et al. (1989). Polar Cleft Structure at 09 MLT: Coordinated Satellite- and Ground-Based Observations. In: Sandholt, P.E., Egeland, A. (eds) Electromagnetic Coupling in the Polar Clefts and Caps. NATO ASI Series, vol 278. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-0979-3_22
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DOI: https://doi.org/10.1007/978-94-009-0979-3_22
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