HR: 1340h
AN: G43B-0811    [Abstracts]
TI: Rotation and impact of the Earth's core on Earth's rotation
AU: Bois, E
EM: eric.bois@obs-nice.fr
AF: Observatoire de la c\^ote d'Azur, Boulevard de l'Observatoire, Nice, F-06304 France
AU: * Rambaux, N
EM: Nicolas.Rambaux@oma.be
AF: Royal Observatory of Belgium, 3, avenue circulaire, Brussels, 1180 Belgium
AU: Dehant, V
EM: Veronique.Dehant@oma.be
AF: Royal Observatory of Belgium, 3, avenue circulaire, Brussels, 1180 Belgium
AU: Van Hoolst, T
EM: tmvh@oma.be
AF: Royal Observatory of Belgium, 3, avenue circulaire, Brussels, 1180 Belgium
AB: This paper investigates the dynamical behavior of a liquid core inside the Earth related to the mantle by inertial coupling. The core-mantle interaction was included in a realistic model of the Earth's rotation, the SONYR model (acronym of Spin-Orbit N-bodY Relativistic model). This model integrates simultaneously the spin-orbit N-body problem and permits to identify the different families of librations/nutations of the terrestrial planets, with special emphasis on the Earth's rotational motion. By using the SONYR model, we study the impact of the core on the rotational motion of the Earth. By comparing the rotation of the Earth considered as a homogeneous body with the rotation of an Earth model with two layers, we establish the signature of the core motion on the librations. We estimate the well-known proper frequencies of the Free Core Nutation and the Chandler Wobble for the two-layer Earth model. Moreover, we investigate for the first time in detail the motion of the core inside the mantle and find, for periods of the order of a year, that the core motions have a larger amplitudes than those of the dynamical motions of the mantle. We present results obtained for various initial conditions and for various oblatenesses.
DE: 5430 Interiors (8147)
DE: 5450 Orbital and rotational dynamics
DE: 1213 Earth's interior--dynamics (8115, 8120)
DE: 1239 Rotational variations
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting