Magnetic hole formation from the perspective of inverse scattering theory

The dynamics of oblique, weakly dispersive nonlinear Alfven waves in the presence of weak resistive damping are investigated numerically through an extension of the derivative nonlinear Schrodinger (DNLS) equation. It is observed numerically that the nonlinear dynamics are organized around the dynamics and allowed interactions of the underlying DNLS soliton families. There are three types of oblique Alfven solitons: the compressive two-parameter soliton and one-parameter bright soliton along with the rarefactive one-parameter dark soliton. The damping of either of these compressive solitons is accompanied by the formation of one or more dark solitons. The implication of these processes is that any initial wave profile containing solitons in its Inverse Scattering Transformation representation, in the presence of weak resistive damping, will result in a leading train of dark solitons. These dark solitons have been identified with magnetic holes, and the results described above are discussed in the context of magnetic hole observations and theory.