Nonlinear Kink Oscillations of Coronal Magnetic Loops
- 222 Downloads
We studied nonlinear kink oscillations of a thin magnetic tube using the cold-plasma approximation. We assumed that the plasma density varies along the tube but does not vary in the radial direction. Using the regular perturbation method, we show that the nonlinearity does not affect the oscillation amplitude. We also calculated the nonlinear correction to the oscillation frequency, which is proportional to the oscillation amplitude squared. As an example, we considered nonlinear oscillations of a coronal magnetic loop of half-circle shape in an isothermal atmosphere with equal plasma temperatures inside and outside the loop.
KeywordsSun Corona Magnetic fields Oscillations
MSR acknowledges the support by a Royal Society Leverhulme Trust Senior Research Fellowship. He is also grateful to the STFC for financial support. A part of this work has been carried out when MSR was a guest at the Centre for Mathematical Plasma Astrophysics of K.U. Leuven. He acknowledges the warm hospitality of the Centre.