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Article
Cluster Observations of Magnetic Field Fluctuations in the High-Altitude Cusp
Annales Geophysicae
  • K. Nykyri, Imperial College London
  • P. J. Cargill, Imperial College London
  • E. Lucek, Imperial College London
  • T. Horbury, Imperial College London
  • B. Lavraud, Centre d'Etude Spatiale des Rayonnements
  • A. Balogh, Imperial College London
  • M. W. Dunlop, Rutherford Appleton Laboratory
  • et al.
Submitting Campus
Daytona Beach
Department
Physical Sciences
Document Type
Article
Publication/Presentation Date
7-1-2004
Abstract/Description

High-resolution (22 vector/s) magnetic field data from Cluster FGM instrument are presented for the highaltitude cusp crossing on 17 March 2001. Despite the quiet solar wind conditions, the cusp was filled with magnetic field turbulence for much of the crossing. Large-scale fluctuations show some correlation between spacecraft but the higher frequency fluctuations show no correlation, indicating that the length scales of these waves are smaller than the spacecraft separation (500 km). In many intervals, there are clear peaks in the wave power around the ion cyclotron frequency (~1 Hz), and there is some evidence for waves at the first harmonic of this frequency. Both left- and right-hand polarised waves are found, with angles of propagation with respect to the ambient magnetic field that range from parallel to perpendicular. The regions of enhanced magnetic field fluctuations appear to be associated with plasma flows possibly originating from a lobe reconnection site. The most coherent, long lasting wave trains with frequencies close to local ion cyclotron frequency occur at a boundary between a sheared flow and a stagnant plasma.

DOI
https://doi.org/10.5194/angeo-22-2413-2004
Publisher
European Geosciences Union
Additional Information

Dr. Nykyri was not affiliated with Embry-Riddle Aeronautical University at the time this paper was published.

Citation Information
K. Nykyri, P. J. Cargill, E. Lucek, T. Horbury, et al.. "Cluster Observations of Magnetic Field Fluctuations in the High-Altitude Cusp" Annales Geophysicae Vol. 22 Iss. 7 (2004) p. 2413 - 2429
Available at: http://works.bepress.com/heidi-nykyri/37/