Precession and nutation for a non-rigid Earth: comparison between theory and VLBI observations

International audienceCoefficients of nutation for a non-rigid Earth developed from the Kinoshita & Souchay (1990) theory for a rigid Earth and from Wahr's transformations (Wahr 1980) to describe the action of the Sun, the Moon and the planets on the space orientation of the Celestial Ephemeris Pole is compared to a series of VLBI measurements of Earth rotation initiated in 1979. Estimates of corrections due the imperfections in the modeling for the largest components are given. Linear trends corresponding to a precession in longitude and a rate in obliquity relative to the IERS Celestial Reference System are also estimated (resp. -3.21 mas/year and -0.26 mas/year). The time variability of terms with periods 433d and 365.26d is studied