Daily measurements of the mean magnetic field of the Sun, 1968–2001: Anomalous distribution?

Abstract

The mean magnetic field (MMF) of Sun was measured in 1968-2001 by four Babcock magnetographs: of Crimean Astrophysical Observatory, CrAO, of Mount Wilson Observatory, MWO, of Wilcox Solar Observatory, WSO, and of Sayan Solar Observatory, SSO (in all nearly 13 thousand daily records). The MMF strengths recorded by these instru- ments on same day, often deviate substantially from each other; this can hardly be explained by purely instrumental/solar causes alone. It is pointed out that (a) each magnetograph represents a linear electro-optical device detecting diminutive, 10 5 10 4 , Zeeman circular polarization of a solar spectral line, with (b) no essential nonliner eects are expected, and (c) observed MMF daily values must be normally distributed around a zero mean. The actual MMF distribution appears to be quite normal for records of CrAO and SSO. Those of MWO and WSO, however, deviate remarkably from normal. The exact physical nature of this abnormity is unknown. It is suggested that true cause might be connected with (a) use of an image-slicer (at MWO and WSO), (b) entanglement of photons, (c) statistical origin of light itself (due to principle of uncertainty: the instrument inevitably influences output), and (d) some instrumental/solar causes of poorly known origin and action.