On stability of rotation of the mean magnetic field of the Sun
Crimean Astrophysical Observatory, Nauchny, Crimea 98409, Ukraine Isaak Newton Institute of Chile, the Crimean Branch e-mail: firstname.lastname@example.org, email@example.com
Corresponding author: V. I. Haneychuk, firstname.lastname@example.org
Accepted: 14 February 2003
New data on the mean magnetic field of the Sun (MMFS) as a star measured at the Crimean Astrophysical Observatory in 1998–2001 are presented. The 34-year time series of the MMFS using similar data from three other observatories (1968–2001, with the total number of daily MMFS values N = 12 428), is considered. It is found that (a) the primary synodic period of the equatorial rotation of solar magnetic field, days, did not vary over the last 34 years, but (b) the average intensity H0 of the photospheric large-scale fields, by modulus, decreased by about 4.5% (with a confidence level of about 80%). The conclusion is made that the longer, 90-year, cycle might be responsible for this potential gradual decrease of H0. The average curve of MMFS variation as plotted with the primary rotational period demonstrates an obvious N-S asymmetry of polarities, perhaps associated with the quadrupole component and “magnetic disequilibrium” of the Sun as a whole.
Key words: Sun: magnetic fields / Sun: rotation
© ESO, 2003