22-Year Variations of the Solar Rotation

We have studied the rotation of the solar atmosphere on the basis of H_α synoptic charts for 117 years (1887 - 2003) and derived the latitude-time diagrams for variation of the rotation periods in the interval of latitude ± 45°. We determined the periods within 8 to 12 year ``windows'', subsequently shifting the ``window'' along the data set, which makes it possible to reveal long-term variations in the solar rotation. It has been shown, that within the interval of latitude ± 20°, the basic rotation period of the background magnetic field of the Sun is 22 years. During odd cycles of solar activity, the rotation rate decelerates, while during even cycles, more rapid rotation is observed. When the sampling ``window'' increases to around 17 years, the 55 to 60 year quasi - period of rotation can be recognized. In this case, the maximum rotation velocity falls roughly on years 1930 and 1990. We consider possible generation of the solar cycle by 22-year period torsion waves interacting with relic magnetic field.