MHD turbulence

Annick Pouquet, The National Center for Atmospheric research, Boulder, USA

This course will present the main differences between MHD and neutral fluid turbulence. After a brief derivation of the magnetohydrodynamic equations, their main features will be presented, like the additional conserved quantities and the corresponding direct or inverse cascades, the breaking of symmetry induced by a mean magnetic field and the weak turbulence description that can be used in that case, the topology and structures of the magnetic field ... Emphasis will also be given to recent results on the nonlocal character of the energy transfer in wavenumber space, and its implications on the formation of small-scale structures.