This thesis describes the studies on the solar interior where turbulent thermal convection plays an important role. The author solved, for the first time, one of the long-standing issues in solar physics, i.e., the maintenance mechanism of the solar differential rotation in the near-surface shear layer. The author attacked this problem with a newly developed approach, the reduced speed of sound technique, which enabled him to investigate the surface and deep solar layers in a self-consistent manner. This technique also made it possible to achieve an unprecedented performance in the solar...

This thesis describes the studies on the solar interior where turbulent thermal convection plays an important role. The author solved, for the first time, one of the long-standing issues in solar physics, i.e., the maintenance mechanism of the solar differential rotation in the near-surface shear layer.