Impact of MHD Turbulence on Thermal Wind Balance in the Sun

Abstract: The possible role of magneto-rotational instability (MRI) and its driven MHD turbulence in the solar interior is studied on the basis of the linear and nonlinear theories coupling with physical parameters, providing solar rotation profile inverted from the helioseismic observation and a standard model for the internal structure of the sun. We find that the MRI venue is confined to the higher-latitude tachocline and lower-latitude near-surface shear layer. It is especially interesting that the MRI-active region around the tachocline closely overlaps with the area indicating a steep entropy rise which is required from the thermal wind balance in the sun. This suggests that the MRI-driven turbulence plays a crucial role in maintaining the thermal wind balance in the sun via the exceptional turbulent heating and equatorward angular momentum transports. The warm pole existing around the tachocline might be a natural outcome of the turbulent activities energized by the MRI.