A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium

Details A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium

2001-07-31

arxiv.org/abs/astro-ph/0107580v1

Astron. Astrophys., 379, 1098-1105 (2001),

Astronomy and Astrophysics

Astrophysics

18 pages, 12 figures, submitted to Astron. Astrophys

Scientific paper

10.1051/0004-6361:20011415

The interaction of a weakly nonlinear Alfv\'enic pulse with an Alfv\'en speed inhomogeneity in the direction perpendicular to the magnetic field is investigated. Identically to the phase mixing experienced by a harmonic Alfv\'en wave, sharp transverse gradients are generated in the pulse by the inhomogeneity. In the initial stage of the evolution of an initially plane Alfv\'enic pulse, the transverse gradients efficiently generate transversely propagating fast magnetoacoustic waves. However, high resolution full MHD numerical simulations of the developed stage of the pulse evolution show that the generation saturates due to destructive wave interference. It is shown that the weakly non-linear description of the generated fast magnetoacoustic wave is well described by the driven wave equation proposed in Nakariakov, Roberts & Murawski (1997), and a simple numerical code (2D MacCromack), which solves it with minimal CPU resources produces identical results to those obtained from the full MHD code ({\it Lare2d}, Arber et al. 2001). A parametric study of the phenomenon is undertaken, showing that, contrary to one's expectations, steeper inhomogenities of the Alfv\'en speed do not produce higher saturation levels of the fast wave generation. There is a certain optimal gradient of the inhomogeneity that ensures the maximal efficiency of the fast wave generation.

Affiliated with

Also associated with

No associations

Rating

A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium 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 A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-359510