Tidal admittance of pole tide.

Abstract

The latitudinal distributions of tidal admittance of pole tide, the amplitude ratio and phase lag between the observed and the equilibrium pole tides in the variation of sea level which is induced by the Chandler wobble in the rotation of the earth, are investigated. In the northern hemisphere, the large amplitude ratios are shown at high and low latitudes, and the phase delays and advances of the observed pole tide with respect to the equilibrium pole tide are shown at high and low latitudes, respectively. Near 45°N, at which the equilibrium pole tide has a maximum amplitude, the observed pole tide approaches the equilibrium. These characteristics of the admittance are pronounced along the east coasts of the oceans in the northern hemisphere. The above mentioned facts suggest qualitatively that the oceans at low latitudes excite the Chandler wobble and those at high latitudes damp it so that the effect of the non-equilibrium part of the pole tide on the wobble vanishes as a whole.