Schematic depiction of the methodology used in this study. The surface rotation rate is extrapolated into the corona via a PFSS model driven by ADAPT-GONG magnetograms. In three dimensions this produces a longitude-latitude grid of rotation rates at the height of the source surface (R_ss = 2.5 R_⊙), the height at which the coronal magnetic field opens into the solar wind. The open flux weighted rotation rate is then calculated from the longitude-latitude grid of rotation rates, however the angular momentum flux in the solar wind is expected to vary with distance from the rotation axis. Therefore a factor of sin θ is introduced into open flux weighted averaging process, giving additional weight to the solar wind close to the equator (represented by the magnitude of the black arrows).