Nonlinear dynamics of the 3D Alfven waves in plasma of ionosphere and magnetosphere

The nonlinear dynamics of the 3D solitary Alfven waves propagating nearly parallel to the external magnetic field in plasma of ionosphere and magnetosphere, which are described by the model of the 3-DNLS equation, is studied analytically and numerically. Under the assumption of negligible dissipative effects the analytical estimates and the sufficient conditions for the stability of 3D solutions of the 3-DNLS equation are obtained, based on the transformational properties of the system's Hamiltonian for the whole range of the equation coefficients. On the basis of asymptotic analysis the solutions asymptotics are presented. To study the evolution of the 3D Alfven solitary waves including propagation of the Alfven waves' beams in a magnetized plasma the equation are integrated numerically using the simulation codes specially developed. The results show that the 3-DNLS equation in non-dissipative case can have the stable 3D solutions in form of the 3D Alfven solitons, and also on a level with them the 3D solutions collapsing or dispersing with time. In terms of the self-focusing phenomenon the results obtained can be interpreted as the formation of the stationary Alfven wave beam propagating nearly parallel to magnetic field, or Alfven wave beam spreading, or the self-focusing of the Alfven wave beam. The influence of the dissipation in the medium on structure and character of evolution of 3D Alfven waves is studied. (C) 2015 Elsevier Ltd. All rights reserved.