Implications of Localized, Acoustic Absorption for Heliotomographic Analysis of Sunspots

Acoustic tomography is emerging as an important tool for mapping the three-dimensional structure of the Sun. Widely used in seismic studies of the Earth, tomography is being applied to probe the structure of magnetically active regions (e.g., sunspots), large-scale convective motions, and the structure of the solar atmosphere. By interpreting solar tomographic data by analogy with terrestrial tomographic data, namely in terms of acoustic travel times, Duvall et al. (1996) argue that strong downflows of matter are present beneath sunspots, a conclusion that lends support to the idea that convective downdrafts play a role in forming and maintaining sunspots.