MHD waves in the solar atmosphere
Erwin Verwichte, University of Warwick
The Sun is the our nearest star and the only one that directly affects the Earth on a daily basis. Its light and heat keeps our planet habitable, but its space weather activity challenges our technology and journey into deep space. We study the solar atmosphere to understand the physical processes that underlie this activity, and that manifests itself through flares, coronal mass ejections, equatorial coronal holes,…
But we also study the Sun because it is only star we can examine in exquisite spatially resolved detail and reveal the stellar processes responsible for the activity cycle, the transport of mass and heat through the chromosphere, heat deposition in the higher atmosphere and the acceleration of the solar wind. We use plasma physics and magnetohydrodynamics (MHD) The magnetically dominated corona also shares much of the physics that is found in magnetically confined fusion experiments.
Magnetohydrodynamic (MHD) waves are prevalent throughout the solar atmosphere and play pivotal roles in the aforementioned processes. I will introduce how the various types of MHD waves manifest themselves at the Sun, illustrated by examples from modern ground-based and space-born observations. In particular, I will focus on studies of waves in thermally active plasmas, both at hot and cool temperatures, that are directly linked to flaring.
I will show how waves can provide insight into magnetic reconnection underlying flares as well as into thermal instabilities that are part of the atmospheric mass cycle.