NONLINEAR MHD WAVES IN THE SOLAR WIND PLASMA STRUCTURES

摘要

We investigate the interaction of magnetohydrody-narnic waves with plasma density inhomogeneities. Our numerical study of the full MHD equations shows that: (A) Plasma density inhomogeneities are a source of non-linear generation of transverse com-pressive waves by a plane Alfven wave, and substantially enhance (by about a factor of 2) the generation of the longitudinal compressive waves. (B) Attained maximal values of the generated transverse compressive waves are insensitive to the strength of the plasma density inhomogeneity and the initial amplitude of the Alfven wave. (C) Efficiency of the generation depends weakly upon the plasmaβparameter. The maximum generated amplitude of transverse compressive wave, up to 32 % of the initial Alfven wave amplitude, is reached for about β =0.5. The results obtained demonstrate that plasma inhomogeneities enhance the efficiency of the non-linear wave coupling.