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. The ratio and correlation coefficient are calculated over the general working range of measured magnetic-field values and in various ranges of field magnitudes. We study variations in both the parameters. We have found the following tenden-cies: i) the parameters show changes with solar cycle 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 distin-guished based on the behavioral patterns of variations in the ratio. We discuss correspondences between these ranges and the known structural objects of the solar atmosphere. This leads to a conclusion that the dependence of the parameters on magnetic-field magnitude and time is connected with the variety of magnetic structural components and their cyclic rearrangements. The reported results may be useful for solving interpretation problems of solar magnetic-field meas-urements and for the cross-calibration of applicable instruments. They can also be used for tasks related to the creation of a uniform long temporal series of solar magnetic-field data from various sources.