  We propose a phenomenological technique for modelling the emergence of active
regions within a three-dimensional, kinematic dynamo framework. By imposing
localised velocity perturbations, we create emergent flux-tubes out of toroidal
magnetic field at the base of the convection zone, leading to the eruption of
active regions at the solar surface. The velocity perturbations are calibrated
to reproduce observed active region properties (including the size and flux of
active regions, and the distribution of tilt angle with latitude), resulting in
a more consistent treatment of flux-tube emergence in kinematic dynamo models
than artificial flux deposition. We demonstrate how this technique can be used
to assimilate observations and drive a kinematic 3D model, and use it to study
the characteristics of active region emergence and decay as a source of
poloidal field. We find that the poloidal components are strongest not at the
solar surface, but in the middle convection zone, in contrast with the common
assumption that the poloidal source is located near the solar surface. We also
find that, while most of the energy is contained in the lower convection zone,
there is a good correlation between the evolution of the surface and interior
magnetic fields.
