[P-EM11] Frontiers in solar physics

[PEM11-P14] Prominence splitting and merging due to interchange instability in helical flux rope

*Takafumi Kaneko¹ (1.Niigata University)

Keywords:solar prominences, solar eruptions, MHD instabilities

We investigated the morphological evolution of solar prominences using MHD simulations. The three-dimensional MHD equations, including thermal conduction and radiative cooling, were solved numerically. In our simulations, a helical flux rope was created via reconnection between a pre-existing coronal arcade field and newly emerging flux. We conducted four simulations, varying the initial shear of the pre-existing arcade and the amount of emerging flux. In all cases, a cool dense prominence was formed within the flux rope due to radiative condensation. Initially, the prominence appeared as a single long thread. As the interchange (flute) instability developed in the flux rope, the prominence was highly deformed, splitting into shorter rotating segments. Over time, these segments eventually merged to reconstruct a single long thread. The prominences erupted in the cases of a larger amount of emerging flux, while the prominences remained stable in the cases of a smaller amount of emerging flux. The typical length of the short segments depended on the initial shear of the pre-existing arcade field, regardless of whether the prominence was eruptive or non-eruptive. The deformation growth rates were higher in the eruptive cases than in non-eruptive cases.