E-W MOTIONS OF LARGE-SCALE MAGNETIC-FIELD STRUCTURES OF THE SUN

By applying a new method of processing daily full-disk magnetograms obtained at the Wilcox Solar Observatory at Stanford University, it has become possible to reveal the pattern of global E-W motions of field structures which appears to reflect large-scale convective plasma motions beneath the photosphere. Structures of E-W velocity of different sign extend from north to south, traversing the equator. The extent of the structures in longitude is 25-degrees-45-degrees, and the velocity amplitude reaches 0.4-degrees-0.5-degrees day-1 (60-70 m s-1 at the equator). Boundaries of E-W flows of different sign correlate with strong, large-scale magnetic field hills. The lifetime of the velocity structures is comparable with that of magnetic field structures.