Mixing, heating and ion-neutral decoupling induced by Rayleigh–Taylor instability in prominence-corona transition regions

This study explores nonlinear development of the magnetized Rayleigh–Taylor instability (RTI) in a prominence-corona transition region. Using a two-fluid model of a partially ionized plasma, we compare RTI simulations for several different magnetic field configurations. We follow prior descriptions of the numerical prominence model (Popescu Braileanu et al. 2021 Astron. Astrophys. 646, A93 (doi:10.1051/0004-6361/202039053), Popescu Braileanu et al. 2021 Astron. Astrophys. 650, A181 (doi:10.1051/0004-6361/202140425) and Popescu Braileanu et al. 2023 Astron. Astrophys. 670, A31 (doi:10.1051/0004-6361/202142996)) and explore the charged-neutral fluid coupling and plasma heating in a two-dimensional mixing layer for different magnetic field configurations. We also investigate how the shear in magnetic field surrounding a prominence may impact the release of the gravitational potential energy of the prominence material. We show that the flow decoupling is strongest in the plane normal to the direction of the magnetic field, where neutral pressure gradients drive ion-neutral drifts and frictional heating is balanced by adiabatic cooling of the expanding prominence material. We also show that magnetic field within the mixing plane can lead to faster nonlinear release of the gravitational energy driving the RTI, while more efficiently heating the plasma via viscous dissipation of associated plasma flows. We relate the computational results to potential observables by highlighting how integrating over under-resolved two-fluid sub-structure may lead to misinterpretation of observational data. This article is part of the theme issue ‘Partially ionized plasma of the solar atmosphere: recent advances and future pathways’.