HR: 1340h
AN: G43B-0807    [Abstracts]
TI: Diurnal and semi-diurnal effect of the atmosphere on the Earth rotationand geocenter motion
AU: * de Viron, O
EM: o.deviron@oma.be
AF: Observatoire Royal de Belgique, Avenue Circulaire, 3, Brussels, B 1180 Belgium
AU: Schwarzbaum, G
EM: schwarzbaumgaetan@hotmail.com
AF: Observatoire Royal de Belgique, Avenue Circulaire, 3, Brussels, B 1180 Belgium
AU: Lott, F
EM: flott@lmd.ens.fr
AF: Laboratoire de Meteorologie Dynamique, Ecole Normale Superieure 24, rue Lhomond , PARIS, 75235 France
AU: Dehant, V
EM: v.dehant@oma.be
AF: Observatoire Royal de Belgique, Avenue Circulaire, 3, Brussels, B 1180 Belgium
AB: The diurnal cycle in the atmosphere, and some of its geodetic consequences, as Earth rotation variation and geocenter motion, are studied, from a one year simulation. We show that the effect on the polar motion is at the level of 0.2 milli arcsecond, and that a geocenter motion of the order of the millimeter is to be expected at diurnal timescale. Nevertheless, the large differences between the results from different models indicate that those results should be taken with caution. In particular, we show that the differences in the pressure cycle between the NCEP, the ECMWF and LMD models are very large, which can have important consequences for the de-aliasing of GRACE, for instance.
DE: 1210 Diurnal and subdiurnal rotational variations
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting