The effect of curvature on quasi-modes in coronal loops

Tom Van Doorsselaere, Arnold Debosscher, Jesse Andries, S Poedts

Research output: Contribution to journalArticleResearchpeer-review


This paper studies quasi-mode oscillations in models of coronal loops that include longitudinal curvature. Using a toroidal coordinate system to incorporate curvature in a basic coronal loop model, the linearized ideal MHD equations are solved for the plasma-beta = 0. As a result of the curvature, quasi-modes with different poloidal wave numbers are coupled resulting in modifications of the frequencies. However, for small curvature, only the coupling of quasi-modes with a neighbouring poloidal wave number remains in first order. In addition, the quasi-mode frequencies are unchanged up to first order in the curvature. The imaginary part of the frequency, however, does change in first order, and quasi-modes are slightly more damped in realistically curved coronal loop configurations.
Original languageEnglish
Pages (from-to)1065 - 1074
Number of pages10
JournalAstronomy & Astrophysics
Issue number3
Publication statusPublished - 2004
Externally publishedYes

Cite this