The Non-Homologous Nature of Solar Diameter Variations
  We show in this paper that the changes of the solar diameter in response to variations of large scale magnetic fields and turbulence are not homologous. For the best current model, the variation at the photospheric level is over 1000 times larger than the variation at a depth of 5 Mm, which is about the level at which f-mode solar oscillations determine diameter variations. This model is supported by observations that indicate larger diameter changes for high degree f-modes than for low degree f-modes, since energy of the former are concentrated at shallower layers than the latter. 
Sabatino Sofia, Sarbani Basu, Pierre Demarque, Linghuai Li (Yale), and   Gerard Thuillier (Service d'A\'eronomie du CNRS)