OBSERVED AND SIMULATED PHOTOSPHERIC VELOCITIES WITHIN INCLINED MAGNETIC FIELDS

摘要

This paper presents a comparison of local helioseismic observations from within inclined magnetic fields with theoretical mode conversion results. Helioseismic holography is the technique used for the observational analysis of two sunspots in active regions, AR9026 and AR9057. It is found that the surface velocities within the penumbrae of the sunspots are dependent on the magnetic field orientation and the line-of-sight angle. Mode conversion theory also finds that the orientation of the magnetic field is a very important factor. Surface velocity ellipses are created for particular inclinations of the magnetic field both theoretically and observationally, and these compare somewhat favourably. It is concluded that mode conversion is a likely cause of the observed effects on the surface velocities within inclined magnetic fields.