Structure and rotation of the large scale solar magnetic field observed at the Wilcox Solar Observatory

Line of sight component of the photospheric large scale magnetic field has been analyzed using the observations made at the Wilcox Solar Observatory since 1976 up to 2004. Magnetic field structure in latitude and in longitude and differential rotation and their variations in time have been studied.A four zones latitudinal structure has been evidenced with boundaries around +25°, 0° and −25° and with a period of polarity change of 22 years about.Quasi-stable over several years longitudinal structure has been revealed in the coordinate system differentially rotating together with the photosphere.An 11-year periodicity has been found in the rotational rate. Additionally in the equatorial zone 4–5-year periodicity has been revealed.