Non-tidal oceanic excitation of nutation and high frequency polar motion estimated from a barotropic ocean model

Author: A. Brzezinski and Rui M. Ponte
Date: 
April 21, 2002 - April 26, 2002
Type: 
Presentation
Venue: 
EGS XXVII General Assembly, Nice
Citation: 

Brzezinski, A., and R.M. Ponte, 2002. Non-tidal oceanic excitation of nutation and high frequency polar motion estimated from a barotropic ocean model, EGS General Assembly, Nice, April 2002.

A new, nearly 8-year long series of ocean angular momentum estimates calculated from a barotropic numerical model is used to study the influence of wind- and pressure-driven ocean signals on nutation and high frequency polar motion. Questions of particular interest to us have to do with (1) the oceanic contribution to the nutation amplitudes, (2) the oceanic excitation of the free core nutation signal, and (3) the po- tential presence of high-frequency, large-scale modes in the global ocean circulation and their possible influence on polar motion. The estimated oceanic effects are com- pared to the atmospheric contributions derived from atmospheric angular momentum data, and those expected from the observations of polar motion and nutation.