Profiles of the Reynolds and Maxwell stresses, defined by Eq. (44). Positive and negative values correspond to the upward and downward AMT. (a–d) Vertical profiles of the Reynolds stress, ℛ_xz, for different values of Co_*. Blue and red colors represent the results from the HD and MHD cases. Green curves show the vertical profiles of the Maxwell stress, ℳ_xz, and the dashed black curves indicate the sum ℛ_xz + ℳ_xz in the MHD simulations. (e) Volume-averaged Reynolds and Maxwell stresses, ${\overline{\mathcal{R}}}_{\mathit{xz}}$ and ${\overline{\mathcal{M}}}_{\mathit{xz}}$, plotted as functions of Co_*.