Convective motions in the deep layers of the solar convection zone are affected by rotation, making the convective heat transport latitude-dependent, but this is not the case in the top layers near the surface. We use the thermal wind balance condition in the deeper layers to estimate the pole–equator temperature difference. Surface observations of this temperature difference can be used for estimating the depth of the near-surface layer within which convection is not affected by rotation. If we require that the thermal wind balance holds in this layer also, then we have to conclude that this must be a layer of strong differential rotation and its characteristics which we derive are in broad agreement with the observational data of the near-surface shear layer.

太阳对流区深层中的对流运动受旋转影响，使对流传热依赖于纬度，但在地表附近的顶层情况并非如此。我们在更深的层中使用热风平衡条件来估计极-赤道温度差。该温度差的表面观察可用于估计对流不受旋转影响的近表面层的深度。如果我们还要求在该层中保持热风平衡，那么我们必须得出结论，该层必须是一个强烈的差动旋转层，我们得出的特征与近地表剪切层的观测数据大体一致。