Variations in Ratio and Correlation of Solar Magnetic Fields in the Fe i 525.02 nm and Na i 589.59 nm Lines According to Mount Wilson Measurements During 2000 – 2012

Abstract

Variations in the solar magnetic-field ratio over 13 years are analyzed, relying on the comparison of simultaneous measurements in two spectral lines at the Mount Wilson Observatory (MWO). The ratio and correlation coefficient are calculated over the general working range of measured magnetic-field values and in various ranges of the field magnitudes. Variations in both parameters are considered. We found the following tendencies: i) the parameters show changes with the cycle of solar activity in the general case; ii) their dependence on magnetic-field magnitude is a nonlinear function of time, and this is especially pronounced in the ratio behavior; iii) several separate ranges of the field magnitudes can be distinguished based on the behavioral patterns of the ratio variations. Correspondences between these ranges and the known structural objects of the solar atmosphere are discussed. This permits us to reach the conclusion that the dependence of parameters considered on the magnetic-field magnitude and time is connected with the variety of magnetic structural components and their cyclic rearrangements. The results represented may be useful for solving interpretation problems of solar magnetic-field measurements and for the cross-calibration of applicable instruments. They can also be of interest for tasks related to the creation of a uniform long temporal series of solar magnetic-field data from various sources.