Three Dimensional Structure of Active Regions

Abstract

We present the preliminary results of the modeling of the three dimensional structure of the magnetic field above the aclive regions observed with Advanced Stokes polarimeter and Dick Dunn telescope at National Solar Observatory, USA. The observed photospheric magnetograms are extrapolated to chromospheric heights using the Fourier expansion technique to compute the potential (current-free) magnetic field in Cartesian geometry. The photospheric surface is assumed to be fiat, but the tilt of the boundary plane with respect to the plane of the sky is taken into account, depending on the location of the active region. The best fit of the observed and computed scatter plot is achieved by considering the height of the chromospheric emission at 800 km.