Open Access

Magnetohydrodynamic waveguide/resonator for Pc3 ULF pulsations at cusp latitudes

  • V. Pilipenko1Email author,
  • E. Fedorov1,
  • N. Mazur1,
  • M. J. Engebretson2 and
  • W. J. Hughes3
Earth, Planets and Space201451:BF03352248

DOI: 10.1186/BF03352248

Received: 9 April 1999

Accepted: 3 June 1999

Published: 6 June 2014

Abstract

We present a possible theoretical model for the generation of travelling Alfven waves by external compressional disturbances in a two-dimensional inhomogeneous plasma. The transformation of a compressional wave mode into Alfven waves guided by the magnetic field is considered in a region with decreased Alfven velocity. This region represents, on the one hand, a waveguide for compressional oscillations, and on the other hand, a resonator with opaque boundaries for Alfven waves. The wave transformation is most effective in a resonant case, when the frequency of a compressional mode approaches the local Alfven frequency of a resonator. This model is applied to the interpretation of Pc3 observations in the cusp region. The mechanism can ensure the selective amplification of magnetosheath turbulence in the Pc3 band in the high-latitude cusp.