A developed stage of Alfven wave phase mixing

Gert Botha, Tony Arber, Valery Nakariakov, Francis Keenan

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)
3 Downloads (Pure)

Abstract

Alfven wave phase mixing is an extensively studied mechanism for dissipating wave energy in an inhomogeneous medium. It is common in the vast majority of phase mixing papers to assume that even though short scale lengths and steep gradients develop as a result of phase mixing, nonlinear wave coupling does not occur. However, weakly nonlinear studies have shown that phase mixing generates magnetoacoustic modes. Numerical results are presented which show the nonlinear generation of magnetosonic waves by Alfven wave phase mixing. The efficiency of the effect is determined by the wave amplitude, the frequency of the Alfven waves and the gradient in the background Alfven speed. Weakly nonlinear theory has shown that the amplitude of the fast magnetosonic wave grows linearly in time. The simulations presented in this paper extend this result to later times and show saturation of the fast magnetosonic component at amplitudes much lower than that of the Alfven wave. For the case where Alfven waves are driven at the boundary, simulating photospheric footpoint motion, a clear modulation of the saturated amplitude is observed. All the results in this paper are for a low amplitude (
Original languageEnglish
Pages (from-to)1186-1194
JournalAstronomy & Astrophysics
Volume363
Issue number3
Publication statusPublished - 2000

Fingerprint

Dive into the research topics of 'A developed stage of Alfven wave phase mixing'. Together they form a unique fingerprint.

Cite this