Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-24T06:11:14.465Z Has data issue: false hasContentIssue false
  • English
  • Français

On the MHD analogue of the Brunt/Väisälä frequency in a magnetized plasma

Published online by Cambridge University Press:  08 November 2000

ALEXANDER I. ERSHKOVICH  and
PETER L. ISRAELEVICH
ALEXANDER I. ERSHKOVICH
Affiliation:
Department of Geophysics and Planetary Sciences, Tel Aviv University, Ramat Aviv, 69978, Tel Aviv, Israel ([email protected])
PETER L. ISRAELEVICH
Affiliation:
Department of Geophysics and Planetary Sciences, Tel Aviv University, Ramat Aviv, 69978, Tel Aviv, Israel ([email protected])
Get access Rights & Permissions [Opens in a new window]

Extract

The MHD analogue of the Brunt/Väisälä frequency, NB, in a magnetized, ideally conducting plasma is obtained, with the vertical component of the magnetic field, Br, taken into account. The magnetic field vector (Br, Bθ, Bϕ) is assumed to satisfy the condition B·∇B ≈ BrdB/dr, which holds in many cases of interest. The frequency NB happens to depend, generally speaking, on the magnetic field orientation relative to the direction of gravity. However, for an isentropic gas, the convective instability criterion is governed by the magnetic field strength (rather than by the orientation of B). In general, the magnetic field has a stabilizing (destabilizing) effect if B/ρ grows (decreases) along the vertical axis r. This conclusion seems not to depend on the specific magnetic field configuration.

Type
Research Article
Information
Journal of Plasma Physics , Volume 64 , Issue 2 , August 2000 , pp. 195 - 200
Copyright
© 2000 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)