Abstract

Although quiet solar magnetic fields are weak and they are difficult to measure, they cover most of the solar disk, even the whole one during epochs of minimal activity. They are basically responsible for the formation of the open flux from the Sun, and, consequently, reliable diagnostics of them are very important. In this study, we use a raster scan covering the whole solar disk of high precision Stokes-meter measurements of the quiet solar magnetic fields in 15 simultaneously recorded lines in the vicinity of Fe ı 525.02 nm. A two-component model atmosphere and the SIR (Stokes Inversion based on Response functions) approach were used for theoretical modeling. Two types of inversion results were obtained for magnetic component: one with kG magnetic field strength, high temperature and small filling factor, and the other one with relatively weak magnetic field (no more then 200 G), low temperature and big filling factor. A possible explanation of such result is briefly discussed. An application of the obtained results for the urgent issue to calibrate SOHO/MDI magnetograms is presented.