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Poster De Conférence Année : 2017

Quasiperiodic modulation of equatorial noise emissions: Cluster and Van Allen Probes observations

F. Nemec
  • Fonction : Auteur
O. Santolik
  • Fonction : Auteur
S. A. Boardsen
  • Fonction : Auteur
G. B. Hospodarsky
  • Fonction : Auteur
J. S. Pickett
  • Fonction : Auteur
W. S. Kurth
  • Fonction : Auteur
C. Kletzing
  • Fonction : Auteur

Résumé

Equatorial noise emissions (fast magnetosonic waves) are routinely observed in the equatorial region of the inner magnetosphere, propagating nearly perpendicular to the ambient magnetic field. Although most events are continuous in time, some are formed by nearly periodically repeating wave elements. We present a survey of these events with the quasiperiodic time modulation observed by the Cluster and Van Allen Probes spacecraft. Local plasma density measurements are used to evaluate the event locations with respect to the plasmapause. It is shown that although the events may occur both inside and outside the plasmasphere, the occurrence of some events is clearly limited to just outside the plasmasphere, with a sudden disappearance at the plasmapause. The fine frequency structure of the events, which is related to the proton gyrofrequency in the source region, is used to determine the source radial distances. Finally, the analysis of multi-spacecraft measurements allows us to estimate the spatiotemporal variability of the events.
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Dates et versions

hal-02861285 , version 1 (08-06-2020)

Identifiants

  • HAL Id : hal-02861285 , version 1

Citer

F. Nemec, O. Santolik, S. A. Boardsen, G. B. Hospodarsky, J. S. Pickett, et al.. Quasiperiodic modulation of equatorial noise emissions: Cluster and Van Allen Probes observations. AGU Fall Meetings, Dec 2017, New Orleans, Louisiane, United States. 51, 2017. ⟨hal-02861285⟩
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