Open AccessCoherent structures in the magnetotail triggered by counterstreaming electron beams
Author(s) -
Mottez F.,
Perraut S.,
Roux A.,
Louarn P.
Publication year - 1997
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97ja00385
Subject(s) - physics , electron , galileo (satellite navigation) , rope , flux (metallurgy) , ion , waveform , computational physics , geophysics , geodesy , geology , quantum mechanics , voltage , engineering , metallurgy , materials science , structural engineering
We describe wave observations carried out on board Galileo during the crossing of a flux rope in the Earth magnetotail. Waveform observations give evidence for transient electrostatic structures. Numerical simulations of the evolution of counterstreaming electron beams with a core of hotter ions have been performed with parameters consistent with Galileo observations during the flux rope crossing. A strongly unstable mode, with a zero real part of the frequency is found to develop and to lead to the generation of coherent electrostatic structures with velocities between ±υ t , the electron thermal velocity. The characteristics of the simulated structures are shown to be similar to those observed in the magnetotail.