Speaker
Description
The nonlinear evolution of Alfvénic modes (torsional, kink, or fluting modes) in magnetic flux tubes is strongly affected by the Kelvin-Helmholtz (KH) instability, which arises from shear flows at the tube boundary. In this study, we show that baroclinic instabilities of Rayleigh-Taylor (RT) type can also emerge at locations in the boundary where the plasma acceleration is directed normal to the boundary. This mechanism plays a significant role in the evolution of fluting modes, leading to the formation of RT-like arrowhead structures alongside the KH-induced vortices and rolls. The concurrent growth of both instabilities is marked by the oscillating nature of the shear flows and the normal acceleration. The interplay between these instabilities introduces complex turbulent dynamics, which may influence the efficiency of resonant damping.
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