Revised value of the dynamical ellipticity of the Earth

Abstract

Summary. A new value of the Earth’s dynamical ellipticity H, defined as the ratio of the difference between the Earth’s polar and mean equatorial moments of inertia to its polar moment of inertia, is derived from the most recent, and accurate, values of the Earth’s equinoxial precession, the EarthMoon mass ratio p and other appropriate data, and a re-evaluation of the numerical procedures involved. This value is an order of magnitude more accurate than its previous values and yields an equivalent improvement in accuracy in other geodynamical quantities derived from H. The new value is consistent with the new System of Astronomical Constants and the new Geodetic Reference System 1980 and is suitable for use in the many astronomical, geophysical and geodetic applications of H.