  We develop a new nonlinear mean field dynamo theory that couples field growth
to the time evolution of the magnetic helicity and the turbulent electromotive
force, $\emfb$. We show that the difference between kinetic and current
helicities emerges naturally as the growth driver when the time derivative of
$\emfb$ is coupled into the theory. The solutions predict significant field
growth in a kinematic phase and a saturation rate/strength that is magnetic
Reynolds number dependent/independent in agreement with numerical simulations.
The amplitude of early time oscillations provides a diagnostic for the closure.
