Rms and absolute value of the latitudinal magnetic field amplitude evolution at r = 0.86   R_⊙. The dotted and dashed lines correspond to the absolute value of the latitudinal component of the magnetic field in the downflows and in the upflows. We selected the downflows part by setting the magnetic field to zero at the points corresponding to a positive v_r on the r = 0.86R_⊙ spherical shell. We averaged the remaining values over the shell to obtain B_θ in downflows, and did the opposite for the upflows selection. The diamond line represents the evolution of the rms latitudinal magnetic field in the purely diffusive (test) case.