Large-scale magnetic field evolution on different time scales

Horizontal transport of large-scale magnetic field in coarse of last three solar activity cycles was studied. The specific displacement of magnetic regions was followed during their lifetime and the horizontal velocity field was inferred. The velocity field was analyzed during the 25 years time interval and cyclic changes of the velocity values were obtained. Velocities were studied in the 320 individual synoptic charts with spatial resolution 5 heliographic degrees in both longitudinal and latitudinal directions. A non-homogeneous transport of the magnetic flux over the solar sphere, superposed on the global differential rotation and meridional circulation was revealed. Both zonal and meridional global axially symmetric velocities vary during the 11-year activity cycle. The non-axially symmetric velocity field creates the large-scale flow structures with lifetime from 4 to 6 Carrington rotations and characteristic scale length from 40 to 60 heliographic degrees in the zonal belt between +/- 60 degrees of the latitude. Also RMS velocity of the non-axially symmetric velocity field varies during the 11-year activity cycle. Long-term relationship between cyclic variations of the velocity parameters and the magnetic flux values is discussed.