FREQUENCY SPLITTING OF FREE CORE NUTATION IN THE EARTH'S MAGNETIC FIELD

摘要

An analysis of the residual discrepancies between the accepted IAU2000 theory and measurements from recent years shows that the structure of these discrepancies is not consistent with predictions. According to this theory, the determinate part of the discrepancies must involve intrinsic oscillations at the free nutation frequency of the core, but a correlation analysis reveals a larger number of harmonics. A model is proposed which can fully explain the two major components of the residual discrepancies between the theory and experiment. The resulting periods are the same as the periods found in the discrepancies between the IAU2000 model and the measurement data.