The thickness of resistivedispersive shocks
Abstract
The purpose of this paper is to examine the thickness of slow, intermediate, and fast shocks described by the resistivedisersive plasma model, which contains two scale lengths: the resistive length λ_{r} and the ion inertial length λ_{i}. It is found that for the case where λ_{r}<<λ_{i}, i.e., for small resistivity, slowly damped wave trains dominate the structure yielding an effective shock thickness much greater than the ion inertial length. When λ_{r}>>λ_{i}, i.e., for large resistivity, the shock structure has a thickness of the order of the resistive length so that it is again much larger than λ_{i}. Thus a minimum thickness is predicted by the resistivedispersive model and occurs for intermediate resistivity: it is found to be a few λ_{i} for the slow shocks in distant magnetotail as well as for subcritical bow shocks and about 20 λ_{i} for intermediate shocks with typical magnetopause parameters. It is shown that the shock thickness also depends critically on the upstream plasma beta, β_{1}=2μ_{0}p_{1}/B_{1}^{2}, small β_{1} values leading to smaller thickness. The effect of regular Newtonian viscosity on the shock thickness is also examined briefly.
 Publication:

Journal of Geophysical Research
 Pub Date:
 June 1992
 DOI:
 10.1029/92JA00138
 Bibcode:
 1992JGR....97.8269H
 Keywords:

 Magnetohydrodynamic Waves;
 Mathematical Models;
 PlasmaElectromagnetic Interaction;
 Shock Waves;
 Solar Terrestrial Interactions;
 Thickness;
 Beta Factor;
 Bow Waves;
 Magnetopause;
 Magnetotails;
 Viscosity;
 Geophysics;
 Space Plasma Physics: Shock waves;
 Magnetospheric Physics: Magnetopause;
 cusp;
 and boundary layers;
 Magnetospheric Physics: Magnetotail;
 Space Plasma Physics: Magnetic reconnection