Authors: Douglas Braun
Affiliation: NorthWest Research Associates, Inc., Colorado Research Associates
Division
Recent developments in local helioseismology are making it possible to probe
thermal, magnetic, and velocity perturbations in the solar interior and on its
far surface. Seismic holography is a flexible, efficient means of imaging solar
features within the interior and far side to a spatial resolution limited by
the diffraction of the acoustic waves used in the analysis. I will describe
the development and application of helioseismic holography to data from MDI/SOHO
and GONG, and its projected application to the Helioseismic and Magnetic Imager
on the Solar Dynamics Observer. Employing data from MDI on SOHO, a daily synoptic
monitor of far-side activity for space weather prediction and other purposes
has been available at http://soi.stanford.edu/data/farside since late 2000.
Seismic holography will also address fundamental questions about the solar interior.
Topics of ongoing exploration include the subsurface nature of supergranulation,
active regions, and meridional circulation, and the correlation of flows with
the generation and transport of solar magnetic fields.
This work is supported by funding from the NSF and from NASA, including the
Living with a Star Targeted Research and Technology Program.