Cascades and dissipation ratio in rotating magnetohydrodynamic turbulence at low magnetic Prandtl number

Franck Plunian (1) , Rodion Stepanov (2)

1 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
2 ICMM - Institute of Continuous Media Mechanics of the RAS

A phenomenology of isotropic magnetohydrodynamic (MHD) turbulence subject to both rotation and applied magnetic field is presented. It is assumed that the triple correlation decay time is the shortest between the eddy turn-over time and the ones associated to the rotating frequency and the Alfvén wave period. For Pm=1 it leads to four kinds of piecewise spectra, depending on four parameters: injection rate of energy, magnetic diffusivity, rotation rate, and applied field. With a shell model of MHD turbulence (including rotation and applied magnetic field), spectra for Pm≤1 are presented, together with the ratio between magnetic and viscous dissipations.

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

Franck Plunian, Rodion Stepanov. Cascades and dissipation ratio in rotating magnetohydrodynamic turbulence at low magnetic Prandtl number. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2010, 82, pp.046311. ⟨10.1103/PhysRevE.82.046311⟩. ⟨insu-00565360⟩