%0 Journal Article
%T Three-dimensional simulations of turbulent spectra in the local interstellar medium
%A D. Shaikh
%A G. P. Zank
%J Nonlinear Processes in Geophysics (NPG)
%D 2007
%I Copernicus Publications
%X Three-dimensional time dependent numerical simulations of compressible magnetohydrodynamic fluids describing super-Alfv¨¦nic, supersonic and strongly magnetized space and laboratory plasmas show a nonlinear relaxation towards a state of near incompressibility. The latter is characterized essentially by a subsonic turbulent Mach number. This transition is mediated dynamically by disparate spectral energy dissipation rates in compressible magnetosonic and shear Alfv¨¦nic modes. Nonlinear cascades lead to super-Alfv¨¦nic turbulent motions decaying to a sub-Alfv¨¦nic regime that couples weakly with (magneto)acoustic cascades. Consequently, the supersonic plasma motion is transformed into highly subsonic motion and density fluctuations experience a passive convection. This model provides a self-consistent explaination of the ubiquitous nature of incompressible magnetoplasma fluctuations in the solar wind and the interstellar medium.
%U http://www.nonlin-processes-geophys.net/14/351/2007/npg-14-351-2007.html