Papers by Gedalin Gedalin
Geophysical Research Letters, 2005
Electric field measurements from a single spacecraft have been used to study ion‐sound turbulence... more 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.
Change of Rankine–Hugoniot Relations during Postshock Relaxation of Anisotropic Distributions
The Astrophysical Journal
Collisionless shocks channel the energy of the directed plasma flow into the heating of the plasm... more Collisionless shocks channel the energy of the directed plasma flow into the heating of the plasma species and magnetic field enhancement. The kinetic processes at the shock transition cause the ion distributions just behind the shock to be nongyrotropic. Gyrotropization and subsequent isotropization occur at different spatial scales. Accordingly, for a given upstream plasma and magnetic field state, there would be different downstream states corresponding to the anisotropic and isotropic regions. Thus, at least two sets of Rankine–Hugoniot relations are needed, in general, to describe the connection of the downstream measurable parameters to the upstream ones. We establish the relation between the two sets.
Uploads
Papers by Gedalin Gedalin