Global geodynamic effects of the atmospheric pressure variations: II. Results

Abstract

On the basis of the NCEP/NCAR atmospheric reanalysis project results, expansion of the Earth surface atmospheric pressure into a final series of spherical harmonics is computed for the period from 2000 to 2012. Mean values as well as seasonal amplitudes and phases are estimated for all the expansion coefficients. On the basis of the atmospheric pressure expansion coefficients a number of atmospheric geodynamical parameters and their seasonal variations are obtained including: the full atmospheric mass, geocenter displacements, the Earth form factor, flattening of the Earth ellipsoid, directions of the Earth inertia axes, flattening of the equatorial section of the Earth ellipsoid and its orientation, as well as the asymetric atmsopehric mass distribution with respect to the equator. A physical interpretation of the estimated values is provided. A comparison with results of other authors is done. It is concluded that the NCEP/NCAR atmospheric reanalysis data are reliable enough for estimation of atmospheric geodynamical parameters with an accuracy adequate to moderm astrometric and geodetic measurements. Refs 4. Figs 4. Tables 1.

Keywords:

atmospheric gravitational potential, geocenter displacements, Earth form factor, polar motion