Nicholas Brummell University of California, Santa Cruz (UC Santa Cruz) A solid explanation of the observed rotational profile of the solar interior has proven remarkably elusive. Helioseismic inferences tell us that the solar convection zone is rotating differentially, that the radiative interior is rotating as a solid body, and that these two regions are joined by a thin transition region, the solar tachocline. This region is remarkably thin, in the sense that the most basic dynamical processes (diffusion, rotational spin down, etc) would have it deeper. There are both purely hydrodynamic and magnetohydrodynamic theories to explain the thinness. We here examine magnetohydrodynamics theories, including both laminar and turbulent components and examining their respective roles.