Magnetospheric boundary (magnetopause) flowed by solar wind plasma is considered to be a thin layer with constant thickness and curvature radius. The plasma parameters and the magnetic field are assumed to obey the ideal incompressible magnetohydrodynamics. A Fourier analysis is used to calculate small perturbations of the magnetic field and plasma parameters near the magnetopause in a linear approximation. The instability growth rate is obtained as a function of the magnetopause thickness, curvature radius, velocity and magnetic field vectors given on the both sides of the magnetopause. The resulting instability is a combination of interchange and Kelvin-Helmholtz instabilities of the magnetospheric boundary. For a fixed plasma velocity, the instability is the strongest in a case of antiparallel magnetic fields at the magnetopause. The instability decreases if the magnetosheath magnetic field deviates from the direction antiparallel to the geomagnetic field. Instability growth rate is an increasing function of plasma velocity component perpendicular to the magnetic field. On the other hand, plasma flow along the magnetic field diminishes the instability growth rate. For zero plasma velocity, the instability growth rate is positive only within a relatively small angle interval for the deviation of the magnetosheath magnetic field from the antigeomagnetic direction. This angle interval depends on the curvature radius and inner structure of the magnetopause.

Date Published: 28 February 2002
PDF: 9 pages
Proc. SPIE 4678, Eighth International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, (28 February 2002); doi: 10.1117/12.458489

Published in SPIE Proceedings Vol. 4678:
Eighth International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics
Gelii A. Zherebtsov; Gennadii G. Matvienko; Viktor A. Banakh; Vladimir V. Koshelev, Editor(s)