Invited_talk abstract details

The goal of local helioseismology is to elicit three-dimensional information about the subsurface (or far-side) structure and dynamics of the Sun from observations of the helioseismic wave field at the surface. The physical quantities of interest include flows, sound-speed deviations, magnetic fields, etc. This is an inverse problem, for which we need to first understand, and be able to solve, the forward problem. Most of the effort towards solving both the forward and inverse problems has assumed weak perturbations where different linear approximations can be applied. In this talk we discuss ways in which progress could be made to amend such limitations.