Oscillations of flux tube bundles and the structure of sunspot magnetic fields

Abstract

Observational aspects of the previously found quasi-hourly oscillations of magnetic fragments in sunspot polar coordinates are investigated. The orientation of the oscillations is shown to be azimuthally anisotropic, with their amplitude reaching a maximum in penumbra at a distance of ∼0.8 sunspot radius (the maximum amplitude is estimated to be 3700 km). Based on the detected deviations of the oscillations from the radial direction, we numerically simulate the horizontal configuration of field lines in the region of the major spots in bipolar groups.