The role of AR topology on excitation, trapping and damping of individual loop oscillations

Details The role of AR topology on excitation, trapping and damping of individual loop oscillations The role of AR topology on excitation, trapping and damping of individual loop oscillations

Dec 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufmsh13a1517s&link_type=abstract

American Geophysical Union, Fall Meeting 2008, abstract #SH13A-1517

Physics

7509 Corona, 7524 Magnetic Fields, 7836 Mhd Waves And Instabilities (2149, 2752, 6050)

Scientific paper

We investigate the role of magnetic field topology on individual dense loop oscillation by the means of 3D MHD numerical simulations of two models of idealized active regions (AR's). The first model of AR is initialized as a straight cylinder surrounded by the fieldlines of the same length and orientation. The second model consists of a force-free dipole magnetic configuration and contains a loop with a higher density than its surroundings. Dipole fieldlines have position dependent length and orientation. We study different ways of excitation of transverse loop oscillations by an external pulse and by a nearly eigenmode excitation implemented inside the loop. We find that perturbation acting directly on a single loop excites oscillations both in cylindrical and dipole loop. However, the leakage of the wave energy is larger in a curved loop compared to straight loop. External excitation of the whole AR is efficient in the excitation of oscillation in the straight cylindrical AR, but results in less efficient excitation in the case of dipole AR loop. We claim that excitation of collective motion of straight fieldlines having the same wave-periods and planes of the oscillations requires much less energy than excitation of dipole fieldlines having position-dependent orientation and wave-periods and being excited individually, not having a collective mode of oscillation. We conclude that coherent motion of straight fieldlines is one of the factors that decreases the energy leakage from an oscillating loop, while individual motions of dipole fieldlines require more energy from the source to produce the loop oscillations, and also lead to higher damping rate compared to the straight field case.

Affiliated with

Also associated with

No associations

Rating

The role of AR topology on excitation, trapping and damping of individual loop oscillations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The role of AR topology on excitation, trapping and damping of individual loop oscillations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The role of AR topology on excitation, trapping and damping of individual loop oscillations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1246497