  We study the effects of vertical outflows on mean-field dynamos in disks.
These outflows could be due to thermal winds or magnetic buoyancy. We analyse
numerical solutions of the nonlinear mean-field dynamo equations using a
two-dimensional finite-difference model. Contrary to expectations, a modest
vertical velocity can enhance dynamo action. This can lead to super-exponential
growth of the magnetic field and to higher magnetic energies at saturation in
the nonlinear regime.
