34th Solar Physics Division Meeting, June 2003
Session 1 Corona I
Oral, Monday, June 16, 2003, 9:00am-12:00noon, Auditorium

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[1.08] Damped Oscillations of Multithreaded Coronal Loops: results of 3D MHD Simulations

L. Ofman, J. Terradas (CUA and NASA GSFC)

Recently, scaling laws of the damping time of coronal loop oscillations were constructed from TRACE observations in the EUV of damped coronal loop oscillations (Ofman and Aschwanden 2002). The scaling laws suggest that the damping of the oscillations is due to phase mixing with anomalously high viscosity or resistivity. The phase mixing dissipation scenario is most likely realized due to the multithread structure of the coronal loops as suggested by observations. We develop a resistive 3D MHD model of an active region coronal loop in low-beta plasma. We model the damping of an active region coronal loop oscillations using the resistive 3D MHD equations. The oscillations are excited by a model “EIT wave” that hits the loop. We investigate the evolution and the damping of the oscillations in a multithreaded loop and compare the results with a cylindrical loop. We find that the damping time is strongly dependent on the resistivity for the multithreaded loop, while for the cylindrical loop the damping time is weakly dependent on resistivity, in agreement with previous analytical results. We investigate the effects of boundary conditions, resistivity, and loop parameters on the damping rate in the multithreaded loop.

The author(s) of this abstract have provided an email address for comments about the abstract: Leon.Ofman@gsfc.nasa.gov

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Bulletin of the American Astronomical Society, 35 #3
© 2003. The American Astronomical Soceity.