Global meteorological analyses from the European Centre for Medium Range Weather Forecasts are employed to compute the atmospheric excitation &PSgr; of the polar motion for the 9-year period of 1980--1988. Both the matter component &PSgr;(motion) are computed, the former with and without the oceanic inverted barometer (IB) effect. It is found that &PSgr;(motion) contributes significantly to the total excitation &PSgr; overall and nonnegligibly to the annual signal in &PSgr;, or the annual wobble excitation, in particular. Our results for the annual wobble excitation, in terms of the prograde component &PSgr;+ and the retrograde component &PSgr;- for January 1, are &PSgr;+= (16.8 milliarc seconds (mas), -93¿) and &PSgr;-=(15.6 mas, -98¿) with IB, and &PSgr;+=(17.3 mas, 101¿) and &PSgr;-=(28.1 mas, -112¿) without IB. These results are within the (rather large) range of previous estimates. The IB effect has a small impact on &PSgr;+, whereas its impact on &PSgr;- is considerable. The (better determined) prograde components &PSgr;+ are then compared with that observed from the Lageos satellite laser range data: (17.3 mas, -61¿). Although the amplitudes are nearly equal, large phase discrepancies exist between the atmospheric and this observed value. The resolution of this discrepancy awaits a better knowledge of the seasonal angular momentum budget on the Earth's surface fluid elements. ¿American Geophysical Union 1991 |