HR: 0800h
AN: NG21B-0530    [Abstracts]
TI: Nonlinear Processes in the Damping of Alfven Solitons
AU: * Hamilton, R L
EM: rhamilton@georgefox.edu
AF: George Fox University, 414 Meridian St. #6125, Newberg, OR 97132, United States
AU: Peterson, D
EM: dpeterson04@georgefox.edu
AF: George Fox University, 414 Meridian St. #6125, Newberg, OR 97132, United States
AB: The dynamics of Alfven solitons in the presence of weak resistive damping is investigated numerically using the derivative nonlinear Schrodinger (DNLS) equation. The solitons studied here represent one-dimensional, weakly nonlinear and weakly dispersive Alfven waves traveling at a small angle to an ambient magnetic field. There are three types of solitons allowed in this case: the two-parameter soliton and the one-parameter bright soliton, which are both compressive, along with the one-parameter dark soliton, which is rarefactive. It is found for a bright soliton and also a normal ( v > vA) two-parameter soliton that with weak resistive damping these solitons have a brief increase in amplitude, speed and energy even though the total wave energy is decreasing. Accompanying this is the formation of one or more dark solitons. A two-parameter soliton will subsequently lose amplitude and speed and eventually disperse away. It is found that a bright soliton will eventually coalesce with the first dark soliton formed during its initial damping to yield a two-parameter soliton. The implication of these processes is that a wide class of initial wave profiles, in the presence of weak resistive damping, will result in a leading train of dark solitons.
DE: 2149 MHD waves and turbulence (2752, 6050, 7836)
DE: 3255 Spectral analysis (3205, 3280)
DE: 3260 Inverse theory
DE: 3285 Wave propagation (0689, 2487, 4275, 4455, 6934)
SC: Nonlinear Geophysics [NG]
MN: 2007 Fall Meeting