Morphology and Dynamics of Solar Prominences From 3d MHD Simulations

Abstract

In this paper we present a numerical study of the time evolution of solar prominences embedded in sheared magnetic arcades. The prominence is represented by a density enhancement in a background-stratified atmosphere and is connected to the photosphere through the magnetic field. By solving the ideal magnetohydrodynamic equations in three dimensions, we study the dynamics for a range of parameters representative of real prominences. Depending on the parameters considered, we find prominences that are suspended above the photosphere, i.e., detached prominences, but also configurations resembling curtain or hedgerow prominences whose material continuously connects to the photosphere. The plasma-β is an important parameter that determines the shape of the structure. In many cases magnetic Rayleigh-Taylor instabilities and oscillatory phenomena develop. Fingers and plumes are generated, affecting the whole prominence body and producing vertical structures in an essentially horizontal magnetic field. However, magnetic shear is able to reduce or even to suppress this instability.

A hybrid Rayleigh-Taylor-current-driven coupled instability in a magnetohydrodynamically collimated cylindrical plasma with lateral gravity

“…35 3D numerical simulations have successfully reproduced the fingers/plumes/ bubbles structures generated by the RT instability. [36][37][38] The analytical RT-CD theory presented in this paper is expected to provide more insight into the early phase of these phenomena.…”

Solar Prominences: “Double, Double… Boil and Bubble”

“…These Lagrangian trajectories also imply that field lines (mainly directed along z) indeed show significant interchange behavior. This aspect may be exaggerated in our simulation by the periodicity assumption: in reality, these field lines are part of an arcade system passing through the prominence matter, and line-tying effects play a role in determining their RayleighTaylor stability properties (Terradas et al 2015). …”

The magnetic Rayleigh–Taylor instability in solar prominences

“…They conjectured that this could be provide an explanation to connect between the observed vertical threads in prominences and horizontal threads in filaments. Terradas et al (2015), using a 3D extension of the 2D model of a normal polarity prominence presented in Terradas et al (2013), investigate the formation of vertical structuring in a 3D prominence model as a result of the magnetic Rayleigh-Taylor instability. By loading mass as to form a low-lying prominence (height 10 4 km) onto the magnetic field and then letting it relax to find a new equilibrium, they found that it went Rayleigh-Taylor unstable.…”

“…They found that the tightly wound tube resulted in quick saturation of the Rayleigh-Taylor instability giving some suggestion as to why plume dynamics are not observed in active region prominences. As with the models of Terradas et al (2015), to connect these to quiescent prominence changes in height and the thickness of density transition (along with larger density contrasts) are possible changes to the model, and intuitively one can expect that these changes would increase the growth of any instability in the model (but calculations should be performed to confirm this).…”