2 Probing the Solar Interior
We cannot observe the solar interior
directly.
Rather, we must infer what is occurring below the surface from measurements made in the solar
photosphere and above. In this section we review the types of observations which provide insight into solar
interior dynamics and discuss what they can tell us, both in principle and in practice. Results from these
observations will be discussed in Section 3.
The most stringent observational constraints on dynamical models of the solar interior are provided by
helioseismology, for which many excellent and much more comprehensive reviews exist; see for
example Gizon and Birch (2005
) in these volumes, and also Gough and Toomre (1991) and
Christensen-Dalsgaard (2002). A more detailed discussion of the solar rotation profile in particular,
including both observational results and modeling efforts, is given by Thompson et al. (2003). Many
earlier reviews of solar rotation are also available, focusing primarily on surface measurements
(Gilman, 1974; Howard, 1984; Schröter, 1985; Rüdiger, 1989; Beck, 2000).
