Equilibrium and stability analysis of magnetospheric plasmas
Abstract
The equilibrium and stability properties of plasmas in the Earth's magnetotail and Jupiter's magnetosphere are considered. A sufficient condition for the stability to ballooning modes of axisymmetric plasmas with equilibrium fieldaligned flows is derived. These modes are found to be unstable, independent of the pressure gradient, if the flow speed approaches a critical speed of the plasma. This analysis is applied to the Jovian magnetosphere and the flow speeds are found to be too small to drive this resonant destabilization. However, in the inner magnetosphere, which is a region of essentially corotational flow, the sufficient condition for stability is violated because of the large destabilizing flow terms. Similar results in the middle magnetosphere are obtained, where fieldaligned flows large enough to violate the condition for stability are consistent with the present data. Finally, equilibrium and stability in the Earth's magnetotail are discussed. A relaxation process to describe equilibrium states is considered. These solutions have the structure of flux ropes containing fieldaligned currents. These results agree with data from the two observations ISEE1 and ISEE2. A sufficient condition for the stability of these states is formulated.
 Publication:

Ph.D. Thesis
 Pub Date:
 1989
 Bibcode:
 1989PhDT........30P
 Keywords:

 Earth Magnetosphere;
 Equilibrium Flow;
 Ionospheric Currents;
 Jupiter (Planet);
 Magnetohydrodynamic Stability;
 Planetary Magnetic Fields;
 Plasmas (Physics);
 Space Plasmas;
 Auroral Zones;
 Critical Velocity;
 Destabilization;
 International Sun Earth Explorer 1;
 Pressure Gradients;
 Stability;
 Launch Vehicles and Space Vehicles