Abstract


  SUPPRESSION OF OSCILLATORY POWER IN EVOLVING MAGNETIC FIELD

  S. Krishna Prasad, Queen's University Belfast, krishna.prasad@qub.ac.uk

It has long been known that surface amplitude of p-mode oscillations is reduced in the presence of magnetic field. This produces regions of suppressed power in commonly built powermaps coincident with the locations of magnetic concentrations. Several theories were proposed to explain this phenomenon, but perhaps the most convincing theory that conforms to a majority of the observed properties is the absorption of p-modes by magnetic fields and partial conversion to magnetoacoustic waves. We investigated the power suppression properties in an evolving magnetic region through a time-dependent study using high spatial resolution observations from DST (ROSA/HARdcam). The results are in agreement with recent simulations.