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 i n the periodogram before the magnetic-field reversal in 1980 was at 27.39 d ays, whereas, after the field reversal, it moved to 26.89 days. The charact er of the rotation of the mean magnetic field in the 21st solar-activity cy cle 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 magneti c field is not a simple copy of the two-sector structure, and has a more co mplex pattern. The amplitudes of the components of the two- and four-sector structures in the 21st solar-activity cycle varied in antiphase. In this c ycle, the Sun changed its field configuration from dipolar to quadrupole tw ice; in the 22nd cycle, this occurred only once.