Advances in our helioseismic view of the Sun

Shravan Hanasoge (Stanford University)

In recent decades, imaging of the solar interior has been made possible through the development and application of techniques of helioseismology which combine mathematical rigour and sophisticated guesswork. Analyses of the high quality observations made by the Michelson Doppler Imager (MDI) instrument onboard the Solar and Heliospheric Observatory (SOHO) satellite have led to continuous progress in our ability to infer subtle aspects of the recondite solar interior. This rush of discoveries has brought with it some skepticism and a need to determine whether the diagnostic agents, namely the waves, indeed behave as we expect them to.

Towards this goal, modeling wave behavior in the Sun using either numerical or analytical techniques is a useful way to proceed. Numerical methods are developed to simulate 3D linear wave propagation in magnetic and non-magnetic environments in a solar-like stratified medium. Helioseismic analyses of the simulated data have provided us with startling insights into the nature of wave interactions and scattering. A number of results will be discussed.