A strategy for MHD simulation of flux rope ejections
Current Developments in Numerical Astrophysics
Paolo Pagano
University of St Andrews
Duncan Mackay (University of St Andrews)
Coronal Mass Ejections (CMEs) are violent and sudden release of magnetic flux and plasma from the solar corona into the interplanetary space. Although they have been observed for decades, many scientific questions remain unanswered. Numerical methods are extensively used to describe these phenomena in the framework of Magnetohydrodynamics (MHD). In particular, the flux rope ejection model can explain many of the observed features, where magnetic structures, flux ropes, are slowly formed in the solar corona where they lie in equilibrium for periods of weeks before being suddenly ejected in few hours. The different time scales involved pose considerable challenges to numerical models, as computational efficiency and model accuracy need to coexist.
Our strategy is to couple two existing numerical models: the Global Non-Linear Force-Free Field (GNLFFF) model that is tailored to describe the slow formation of flux ropes and the numerical MHD model MPI-AMRVAC that keeping a general approach is suitable to describe the fast CME evolution. The two models are coupled two ways, in order not only to simulate the whole life span of a single flux rope, but also to use this strategy to perform a continuous simulation of the global corona where flux ropes are constantly under formation.
In the presentation we will describe the main pillars of our model that consist of our own latest developments to the robust MPI-AMRVAC code:
- 3D interpolation of variable between different space grids
- module to numerically solve MHD equations in terms of the potential vector A
13:30 - 15:00