Proceedings of the International Astronomical Union

Contributed Papers

MHD waves at a spherical interface modelling coronal global EIT waves

M. Douglasa1 and I. Ballaia1

a1 SP2RC, Department of Applied Mathematics, University of Sheffield, Sheffield S3 7RH, UK email: mark.douglas@sheffield.ac.uk; i.ballai@sheffield.ac.uk

Abstract

Energetically eruptive events such as flares and coronal mass ejections (CMEs) are known to generate global waves, propagating over large distances, sometimes comparable to the solar radius. In this contribution EIT waves are modelled as waves propagating at a spherical density interface in the presence of a radially expanding magnetic field. The generation and propagation of EIT waves is studied numerically for coronal parameters. Simple equilibria allow the explanation of the coronal dimming caused by EIT waves as a region of rarified plasma created by a siphon flow.

Keywords

  • waves;
  • hydrodynamics;
  • Sun: Corona;
  • Sun: oscillations