Abstract
The normal mode spectrum for the linearized MHD equations is
investigated for a cylindrical equilibrium. This spectrum is examined
for zero perpendicular thermal conduction, with both zero and non-zero
scalar resistivity. Particular attention is paid to the continuous
branches of this spectrum, or continuous spectra. For zero resistivity
there are three types of continuous spectra present, namely the Alfven,
slow, and thermal continua. It is shown that when dissipation due to
resistivity is included, the slow and Alfven continua are removed and
that the thermal continuum is shifted to a different position (where the
shift is independent of the exact value of resistivity). The 'old'
location of the thermal continuum is covered by a dense set of nearly
singular discrete modes called a quasi-continuum. The quasi-continuum is
investigated numerically, and the eigenfunctions are shown to have rapid
spatial oscillating behavior. These oscillations are confined to the
most unstable part of the equilibrium based on the Field criterion, and
may be the cause of fine structure in prominences.
Original language | English |
---|---|
Pages (from-to) | 265-289 |
Journal | Solar Physics |
Volume | 142 |
DOIs | |
Publication status | Published - 1 Dec 1992 |
Keywords
- Coronal Loops
- Magnetohydrodynamic Waves
- Solar Corona
- Solar Prominences
- Thermal Conductivity
- Chromosphere
- Fine Structure
- Solar Temperature