Rotation of the solar mean magnetic field from 1968-1996

Data on the solar mean magnetic field obtained at the Crimean, Mount Wilson, and Stanford Observatories in 1968-1996 are analyzed. The total number of separate measurements was N = 10 383. The main synodic period of the solar rotation for this time interval is 26.92 +/- 0.01 days. The maximum peak in the periodogram before the magnetic-field reversal in 1980 was at 27.39 days, whereas, after the field reversal, it moved to 26.89 days. The character of the rotation of the mean magnetic field in the 21st solar-activity cycle was different from that for the 22nd cycle, but the dominant period (26.92 days) did not change. The observed four-sector structure of the magnetic field is not a simple copy of the two-sector structure, and has a more complex pattern. The amplitudes of the components of the two- and four-sector structures in the 21st solar-activity cycle varied in antiphase. In this cycle, the Sun changed its field configuration from dipolar to quadrupole twice; in the 22nd cycle, this occurred only once.