Hydrological Excitation of Polar Motion Derived from GRACE Gravity Field Solutions

Figure 4

Amplitudes (left column) and phases (right column) of annual oscillations at every grid point computed from GRACE solutions and CPC and GLDAS models. The reference date for the phase is 2004 January 1, 0h UTC. The prominent annual signal are located in the monsoon regions.

(a)

(b)

(c)

(d)

(e)

(f)