October 14, 2011, 12:00 pm - 1:00 pm

October 14, 2011, 12:00 pm - 1:00 pm

Resonant Absorption in Coronal Loops

Dr. Jaume Terradas,Departament de Fisica, Universitat Illes Balears, E-07122 Palma de Mallorca (Spain)

Resonant absorption is a candidate to explain the strong damping of transverse loop oscillations reported with TRACE. In this talk we will mainly focuson the time-dependent aspects of this mechanism. First, we will show how the process of mode conversion works in a simple one-dimensional cylindrical model. Then, the extension to a two-dimensional model, representing a multi-stranded loop model, will be presented. One of the main results is that the damping mechanism is not compromised by the complicated geometry of the model. Finally, the results from a three-dimensional nonlinear numerical study of the kink oscillation will be described in detail. We will show the development of a shear instability at the tube boundary and we will discuss the possible effects of this instability on the process of resonant absorption.