Decomposition of the total flux of angular momentum (solid black) into meridional circulation (long-dashed magenta), shear turbulence (dotted blue), and IGW (short-dashed red) in the 1 M_⊙ models computed with and without IGW (left and right panels respectively). Bold lines indicate negative values for the fluxes , , or , when angular momentum is transported towards the central regions by the corresponding mechanism; in the case of meridional circulation and of shear turbulence this corresponds respectively to clockwise currents (U₂ > 0) and to a positive Ω gradient. The profiles are shown at three different ages along the PMS. Shaded areas correspond to convective regions.