Space Research Center, PAS, Bartycka 18a, 00-716 Warsaw
Time variations of Chandler, annual, semiannual, semi-Chandler oscillations of polar motion in the 20th century are presented. For the first time the semi-Chandler oscillation was separated from the semiannual one. Correlation of amplitude variations of semi annual and semi-Chandler oscillations with variations of Atmospheric Angular Momentum and solar acitvity were analyzed.