CONSEQUENCES OF AN ENHANCED POLE TIDE

The pole tide is the response of earth's oceans to a free wobble. It has been widely assumed that the response is an equilibrium one; such a response would involve no dissipation of wobble energy and would result in a tide of small amplitude, roughly half cm. An equilibrium tide would force the part of the wobbling rotation pole to be slightly elliptical (c0.01 ellipticity) and would contribute about one month to the observed 14-month Chandler Wobble period. Yet a greatly enhanced pole tide, with amplitude typically five times the predicted equilibrium value, has long been observed in the North and Baltic seas. In recent years much evidence has been gathered (through diverse data analysis techniques) which suggests that the global oceanic response is also nonequilibrium. In this paper a theory which accounts for the effects of an arbitrary tide rotation has been developed and applied to situations of uniform global enhancement and enhancement in the North and Baltic seas only.- Author