Relative dipole strength plotted against the local Rossby number Ro_ℓ for two different aspect ratios: η = 0.2 (upper panel) and η = 0.6 (lower panel). Each type of symbol is associated to a specific density stratification (from Boussinesq, i.e. N_ρ = 0 to stratified simulations corresponding to N_ρ = 3). The size of the symbol was chosen according to the value of the modified Elsasser number (Eq. (13)). Vertical lines are tentative transitions between dipolar and multipolar dynamos.