Abstract:
Using the data on sunspot groups compiled during 1879-
1975, we determined variations in the differential rotation coefficients A
and Β during the solar cycle. The variation in the equatorial rotation rate A
is found to be significant only in the odd numbered cycles, with an ampli
tude ~ 0.01 μrads–1. There exists a good anticorrelation between the
variations of the differential rotation rate Β derived from the odd and even
numbered cycles, suggesting existence of a '22-year' periodicity in B. The
amplitude of the variation of Β is ~ 0.05 μ rad s–1.
