%0 Journal Article
%@ 0094-8276
%A Balikhin, M
%A Walker, S
%A Treumann, R
%A Alleyne, H
%A Krasnoselskikh, V
%A Gedalin, M
%A Andre, M
%A Dunlop, M
%A Fazakerley, A
%D 2005
%F discovery:162799
%I American Geophysical Union
%J Geophysical Research Letters
%N 24
%T Ion sound wave packets at the quasiperpendicular shock front
%U https://discovery.ucl.ac.uk/id/eprint/162799/
%V 32
%X Electric field measurements from a single spacecraft have been used to study ion-sound turbulence observed within the Earth's bow shock. The observed frequency of the ion-sound waves can be both lower and higher than the local electron cyclotron frequency depending upon the direction of wave propagation in the plasma rest frame. The ion-sound waves observed upstream of the ramp can not be generated either by an instability related to the gradient in the electron temperature or an electric current within the ramp. A comparison of wave vectors for distinctive wave packets indicate that non-stationary, short scale current layers formed in the processes of the ramp evolution might be the source of the free energy for such waves.
%Z Copyright 2005 by the American Geophysical Union