Magnetohydrodynamic Instabilities in Solar Prominences

This work aims to understand of the nature of the magnetic environment which guides the evolution of solar prominences on both large and small scales, of which little is known. By understanding the large-scale evolution of prominences through investigation of eruptive instabilities we can gain insight into how to observationally recover in 3D key features of the torus instability. Through the small-scale evolution we gain knowledge of the fundamental nature of a rarely observed phenomena, the magnetic Rayleigh-Taylor instability, and its manifestation within the prominence substructure. This insight has allowed us to determine the likely magnetic properties of the prominence plasma. We have used imaging and spectropolarimetric data from both satellites and ground-based telescopes. Using stereoscopic techniques we reconstructed features of a solar prominence in 3D utilising pairs of satellites with large seperation angles. By developing novel edge-detection techniques, and iterating upon parametric fitting techniques we conducted a detailed kinematic analysis of an erupting prominence. We have measured the fundamental properties of large numbers of falling plumes within prominences and explained their origins through the RTI. We then supported these observations with ideal-MHD code MANCHA. We have confirmed the role of the TI in an prominence eruption. We have measured fundamental properties of plume with a large number of events. By understanding the TI we allow for the advancement of space-weather prediction. By understanding the RTI we gain insight into the magnetic environment of a prominence

2D and 3D Analysis of a Torus-unstable Quiet-Sun Prominence Eruption

The role of ideal-MHD instabilities in a prominence eruption is explored through 2D and 3D kinematic analysis of an event observed with the Solar Dynamics Observatory and the Solar Terrestrial Relations Observatory between 22:06 UT on 2013 February 26 and 04:06 UT on 2013 February 27. A series of 3D radial slits are used to extract height–time profiles ranging from the midpoint of the prominence leading edge to the southeastern footpoint. These height–time profiles are fit with a kinematic model combining linear and nonlinear rise phases, returning the nonlinear onset time (t nl) as a free parameter. A range (1.5–4.0) of temporal power indices (i.e., β in the nonlinear term ${(t-{t}_{\mathrm{nl}})}^{\beta }$) are considered to prevent prescribing any particular form of nonlinear kinematics. The decay index experienced by the leading edge is explored using a radial profile of the transverse magnetic field from a PFSS extrapolation above the prominence region. Critical decay indices are extracted for each slit at their own specific values of height at the nonlinear phase onset (h(t nl)) and filtered to focus on instances resulting from kinematic fits with ${\chi }_{\mathrm{red}}^{2}\lt 2$ (restricting β to 1.9–3.9). Based on this measure of the critical decay index along the prominence structure, we find strong evidence that the torus instability is the mechanism driving this prominence eruption. Defining any single decay index as being "critical" is not that critical because there is no single canonical or critical value of decay index through which all eruptions must succeed