Fig. 9

Differences of the polar motion excitation functions for the oceans \(\chi ^\text{O}\) derived from GRACE GFZ RL06 gravity field solutions by applying (1) only the DDK filter (green), (2) the DDK filter and the gain factors k (black) and (3) the DDK filter, the gain factors k and the scaling factors \(f^i\) (red) with respect to the polar motion excitation functions derived from the ocean model ECCO (left) and from ESMGFZ data (right)