Direct and inverse cascades in the geodynamo

0330263 - GFÚ 2010 RIV DE eng J - Journal Article
Reshetnyak, M. - Hejda, Pavel
Direct and inverse cascades in the geodynamo.
Nonlinear Processes in Geophysics. Roč. 15, č. 6 (2008), s. 873-880. ISSN 1023-5809. E-ISSN 1607-7946
R&D Projects: GA AV ČR IAA300120704
Institutional research plan: CEZ:AV0Z30120515
Keywords : geodynamo * forward and inverse cascades * magnetic field
Subject RIV: DE - Earth Magnetism, Geodesy, Geography
Impact factor: 1.022, year: 2008
www.nonlin-processes-geophys.net/15/873/2008/

The rapid rotation of planets causes cyclonic thermal turbulence in their cores which may generate the largescale magnetic fields observed outside the planets. We investigate numerically a model based on the geodynamo equations in simplified geometry, which enables us to reproduce the main features of small-scale geostrophic flows in physical and wave vector spaces. We find fluxes of kinetic and magnetic energy as a function of the wave number and demonstrate the co-existence of forward and inverse cascades. We also explain the mechanism of magnetic field saturation at the end of the kinematic dynamo regime.
Permanent Link: http://hdl.handle.net/11104/0176092