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Titel |
Origin of the turbulent spectra in the high-altitude cusp: Cluster spacecraft observations |
VerfasserIn |
K. Nykyri, B. Grison, P. J. Cargill, B. Lavraud, E. Lucek, I. Dandouras, A. Balogh, N. Cornilleau-Wehrlin, H. Rème |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 24, no. 3 ; Nr. 24, no. 3 (2006-05-19), S.1057-1075 |
Datensatznummer |
250015529
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Publikation (Nr.) |
copernicus.org/angeo-24-1057-2006.pdf |
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Zusammenfassung |
High-resolution magnetic field data from Cluster Flux Gate Magnetometer (FGM)
and the Spatio-Temporal Analysis of Field Fluctuations (STAFF) instruments
are used to study turbulent magnetic field fluctuations during the
high-altitude cusp crossing on 17 March 2001. Despite the quiet solar
wind conditions, the cusp was filled with magnetic field turbulence whose
power correlates with the field-aligned ion plasma flux. The magnetic field
wave spectra shows power law behavior with both double and single slopes with
break in the spectra usually occurring in the vicinity of the local ion
cyclotron frequency. Strong peaks in the wave power close to local ion
cyclotron frequency were sometimes observed, with secondary peaks at higher
harmonics indicative of resonant processes between protons and the waves. We
show that the observed spectral break point may be caused partly by damping
of obliquely propagating kinetic Alfvén (KAW) waves and partly by
cyclotron damping of ion cyclotron waves. |
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