Frequencies Solar p-mode frequencies are the basic input data to helioseismology inversions of interior structure and rotation. This plot shows frequencies determined from the MDI medium-l program. Additional figures and information can be found here . That work is in progress. A preprint of a note to ApJ is available.
Figures are here.
The solar interior structure is shown as differential sound speed profiles. There are three regions where the model does not yet reflect the actual Sun. There is a bump in sound speed just beneath the base of the convection zone. Again some evidence for turbulence affecting mean molecular weight. The reason for this is not understood but the siesmic-radius leads to a difference in the sound speed profile with depth that may explain the discrepency between the observations and the model near the surface.