Applications of the KSM03 Harmonic Development of the Tidal Potential

Abstract

The KSM03 harmonic development of the Earth tide-generating potential [TGP] (Kudryavtsev 2004) includes 26,753 terms of amplitudes down to the level of 1 × 10⁻⁸ m²/s² and is made in a reference frame defined by the true geoequator of date with an origin at the point — that being the projection of the mean equinox of date. An advantage of that choice for the reference frame is the TGP series have TDB time argument and do not include a much less stable UT1 time argument necessary to eventually calculate the TGP values in the Terrestrial reference frame [TRF]. It makes the series of KSM03 development valid over a long-term interval of time (1000–3000), and the relevant accuracy of the gravity tides calculation is estimated to be at the sub-nGal level.

For consistence with the available Earth tide analysis programs (like ETERNA) the coefficients of the KSM03 series have been re-calculated in the TRF and transformed into the HW95 (Hartmann and Wentzel 1995) normalization and format (in total 28806 waves). The KSM03 harmonic development of the Earth TGP represented in the standard HW95 format is available at http://lnfml.sai.msu.ru/neb/ksm/tgp/ksm03.dat. It can be directly used by nutation theories and in precise calculations of tidal effects observed in the TRF.

On the base of the KSM03 series we obtained compact analytical representation of variations of the geopotential coefficients caused by the solid Earth tides for the case of frequency-independent Love numbers.