Magnetothermal instabilities in coronal arcades |
| |
| Authors: | R C Ireland A W Hood and R A M Van Der Linden |
| |
| Institution: | (1) Department of Mathematical and Computational Sciences, University of St. Andrews, KY16 9SS St. Andrews, Fife, Scotland, U.K.;(2) Present address: Department of Mathematics and Statistics, University of Birmingham, B15 2TT Edgbaston, Birmingham, England, U.K.;(3) Present address: Jet Joint Undertaking, OX14 3EA Abingdon, England, U.K. |
| |
| Abstract: | The normal mode spectrum for the linearized MHD equations is investigated for a plasma in a cylindrical equilibrium. The equations describing these normal modes are solved numerically using a finite element code. The ballooning equations that describe localized modes are manipulated and a dispersion relation derived. It is shown that as the axial wave numberk is increased, the fundamental thermal and Alfvén modes can coalesce to form overstable magnetothermal modes. The ratio between the magnetic and thermal terms is varied and the existence of the magnetothermal modes examined. The corresponding growth rates are predicted by a WKB solution to the ballooning equations. The existence of these magnetothermal modes may be significant in the eruption of prominences into solar flares. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
