The mean-field dynamo model in geodynamo

The 2D Parker's mean-field dynamo equations with a various distributions of the alpha- and omega-effects are considered. We show that smooth profiles of alpha and omega can produce dipole configuration of the magnetic field with the realistic magnetic energy spectrum. We emphasize that fluctuating alpha-effect leads to increase of the magnetic energy at the small scales, breaking the dipole configuration of the field. The considered geostrophic profiles of alpha and omega correspond to the small-scale polarwards/equatorwards travelling waves with the small dipole field contribution. The same result is observed for the dynamic form of the alpha-quenching, where two branches of the weak and strong solution coexist.