  Context. Three-dimensional spherical dynamo simulations carried out within
the framework of the anelastic approximation have revealed that the established
distinction between dipolar and multipolar dynamos tends to be less clear than
it was in Boussinesq studies. This result was first interpreted as a direct
consequence of the existence of a larger number of models with a high
equatorial dipole contribution, together with an intermediate dipole field
strength. However, this finding has not been clearly related to specific
changes that would have been introduced by the use of the anelastic
approximation. Aims. In this paper, we primarily focus on the effects of
choosing of a different mass distribution. Indeed, it is likely to have as
large consequences as would taking a stratified reference state into account,
especially when comparing our results to previous Boussinesq studies. Methods.
Our investigation is based on a systematic parameter study of weakly stratified
anelastic dynamo models. Results. We show that the tendencies highlighted in
previous anelastic dynamo simulations are already present in the Boussinesq
limit. Thus they cannot be systematically related to anelastic effects.
Actually, a central mass distribution can result in changes in the magnetic
field topology that are mainly due to the concentration of convective cells
close to the inner sphere.
