PhD Seminar: Llorenç Melis, Estudiant del Programa de Doctorat de Física — Surface waves and KHi in a prominence-corona interface: effect of the ambipolar diffusion

There are a wide variety of phenomena in solar prominences, such as waves, instabilities or mass flows. Observations have shown the ubiquitous presence of MHD waves and the Kelvin-Helmholtz instability (KHi) in solar prominences. In this work we study the behaviour of surface MHD waves that appear in a structured plasma, such as a magnetic interface, and the triggering of the KHi when a shear flow is present. We use an interface model that consists of a partially ionised prominence region and a fully ionised coronal region, with a straight and constant magnetic field parallel to the interface. There is a longitudinal flow in the prominence region. The plasma is compressible and the role of ambipolar diffusion, that represents the collisions between charged and neutral particles, is taken into account in the prominence region. We will discuss the general mathematical treatment of surface MHD waves in this model and analyse some limit cases analytically. Such results will be compared with those of previous studies. We will also present some initial numerical results of the full problem and discuss the next steps in this ongoing project.

Sala de Seminaris, 3r pis dpt. Física, UIB