Energy fluxes and ohmic dissipation in the earth's core

Simulations have shown that convection-driven geodynamo models can produce reversing magnetic fields of a similar strength to those of the geomagnetic field. These simulations suggest that the ohmic dissipation arising from the geodynamo is not due solely to the largest scale harmonics of the magnetic field, but is dominated by contributions from smaller scale components. It is argued that, in order to produce a vigorous reversing dynamo resembling the geodynamo, ohmic dissipation of between 1 and 2 TW is required.