The Need for Control Experiments in Local Helioseismology

The key to local helioseismology is the effective application of local seismic diagnostic techniques to determine the structure of the solar interior with the finest possible resolution. The extent and magnitude of the supergranular return flow and the nature of thermal anomalies, flows, and magnetic-field configurations in and near active regions are phenomena on which we hope local helioseismic analyses will shed clear light. However, current applications of local seismic methods produce ambiguous and inconsistent interpretations. It is clear that in order to make further progress, evaluation and refinement of local analysis techniques, and the development of procedures that can separate magnetic effects, subsurface flows, and sound-speed variations will prove critical. We believe substantial progress in this area can be made by conducting control experiments based on magnetoacoustic-gravity waves propagating through specified models of subphotospheric anomalies. In this paper we describe the need for such an effort and developments currently under way to produce the tools necessary to implement a validation and testing program.