Three-dimensional simulations of turbulent spectra in the local interstellar medium
| Autor: | D. Shaikh, G. P. Zank |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Nonlinear Processes in Geophysics, Vol 14, Iss 4, Pp 351-359 (2007) |
| Druh dokumentu: | article |
| ISSN: | 1023-5809 1607-7946 |
| Popis: | Three-dimensional time dependent numerical simulations of compressible magnetohydrodynamic fluids describing super-Alfvénic, 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 Alfvénic modes. Nonlinear cascades lead to super-Alfvénic turbulent motions decaying to a sub-Alfvénic 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. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|