Latitude Migration of Sunspot Groups

Characteristics of latitude migration of sunspot groups in the northern and southern hemispheres are investigated by using the Royal Greenwich Observatory data set from the years 1874 through 1999. Latitude migration of sunspot groups is found to be represented by a binomial formula, which quantitatively describes the law. Latitude migration velocity of sunspot groups is largest at the beginning of a Sporer solar cycle, and as the solar cycle progresses, it decreases with time, with an average of about 1-degrees6 yr(1) during a solar cycle. Two different methods have been employed to confirm that latitude migration in both hemispheres is statistically the same.