Structure of magnetic field B in observed and subsurface layers (Solov’ev & Kirichek 2009). The dashed lines show the mass flows near the sunspot in accordance with local helioseismology data. L is the depth, counted downward from photosphere, ζ is the Wilson depression. L indicates the level of lower magnetic boundary, from which the magnetic flux tube of the sunspot sharply expands downward. The magnetic field in deeper layers is weakened and entangled in the convection motion. It decreases in a diffuse irregular form.