| Presenter: | Michael Demidov |
| Affiliation: | Institute of Solar-Terrestrial Physics, Irkutsk |
| Title: | An extended line-ratio method application: comparison of large-scale solar magnetic field observations in different spectral lines and observatories |
| Authors: | M.L. Demidov, E.M. Golubeva, R.M. Varetsky |
| Form: | poster |
| Abstract: | Comparisons of solar magnetic field observations in different spectral lines (main papers are: Howard \& Stenflo, 1972, Solar Phys., 22, 402; Stenflo, 1973, Solar Phys., 32, 41; Ulrich, 1992, ASP Conf. Ser., 26., 265) and in different observatories (recent papers: Wenzler et al., 2004, A\&A, 127, 1031; Tham et al., 2005, ApJ Suppl., 156, 295) are of crucial importance for understanding the nature of solar magnetism, for mutual instruments calibration, and for some connected issues (e.g. for the construction of common data sets for studying temporal variations of different parameters: rotation, solar irradiance, open flux etc.). In this report we explore the distribution across the solar disk of the magnetic strength ratios (MSR’s) in different combinations of spectral lines using Stokes-meter observations of large-scale magnetic fields made at Sayan observatory, as well as of the MSR’s in different combinations of observatories (Sayan, Wilcox solar observatory, Kitt Peak, SOHO/MDI, Mount Wilson). It was found that along with expected center-to-limb variations (CLV) of MSR’s when different lines are used, there are significant polar-equatorial asymmetries of CLV’s in some cases. This is quite a new result with important implications on various aspects such as the geometry of magnetic fields, or the extrapolation of magnetic fields to the corona, etc. The results of comparing the experimental MSR CLV’s with 1.5D and 2D theoretical simulations in the framework of two-component flux tubes models are presented. |
| Session: | 3. Nature of solar magnetic fields as revealed by polarimetry |
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