MERIDIONAL MOTIONS OF SUNSPOT GROUPS DURING 11 ACTIVITY CYCLES

Greenwich data (1874-1976) are used for a time-dependent analysis of m eridional motions of sunspot groups. We obtain the latitude-dependence of meridional motions of sunspot groups with respect to a mean latitu de determined for half-year intervals. The daily meridional motions of groups are also given separately for growing and decaying sunspot gro ups. The development is determined from changes of sunspot areas. Our results are compared with the reductions performed by Howard (1991b) u sing the Mt. Wilson sunspot data from 1917 until 1985: Although we hav e smaller errors, we do not find any significant drift. We also do not find different trends in the meridional motions of growing as compare d to decreasing sunspots.