  Magnetic field amplification by a fast dynamo is seen in local box
simulations of SN-driven ISM turbulence, where the self-consistent emergence of
large-scale fields agrees very well with its mean-field description. We
accordingly derive scaling laws of the turbulent transport coef- ficients in
dependence of the SN rate, density and rotation. These provide the input for
global simulations of regular magnetic fields in galaxies within a mean-field
MHD framework. Using a Kennicutt-Schmidt relation between the star formation
(SF) rate and midplane density, we can reduce the number of free parameters in
our global models. We consequently present dynamo models for different rotation
curves and radial density distributions.
