Inversion method for deriving physical properties of subsurface magnetic field from surface magnetic field evolution.
I. Concept and Mathematical Description
We present a method for solving an inverse problem of flux emergence that transports subsurface magnetic flux from an invisible solar interior to a visible solar surface, thereby producing active regions on the Sun. A key feature of this method is to introduce flux-emergence function that characterizes how the flux emergence proceeds. On the basis of this function the method was developed for deriving physical properties of a subsurface magnetic field from observed evolution of surface magnetic field, in which a curve-fitting analysis is applied to an evolutionary relation between emerged (unsigned) magnetic flux and relative magnetic helicity. The evolutionary relation between these two quantities could be used for a quantitative classification of active regions having full of variety in size, magnetic field strength, and magnetic field configuration.
Reference
Magara, T.
Journal of the Korean Astronomical Society, 50, 179
