Nonlinear Phenomena in Complex Systems, 2001, Vol.4, No.1, pp.94--105

NONLINEAR PHENOMENA IN COMPLEX SYSTEMS
An Interdisciplinary Journal

2001, Volume 4, Number 1, pp.94-105

Time-Delay Study of Earth Orientation Parameters at Inter-Annual Time Scales
P. Manneville

We proceed to a reanalysis of time series of the Earth Orientation Parameters available from IERS [4] using Takens time-delay embedding technique [5]. Focusing on intermediate time scales rather than short ones as done in [3], we extract oscillations corresponding to Chandler wobble by singular-value decomposition [7] of the time-series of the Celestial Ephemeris Pole position (PMX,PMY) on the period 1890-2000. A Pi phase-shift of the oscillation around 1930 is pointed out explicitly. A similar study of the length-of-day time series shows strong correlation with indices measuring the strength of the ENSO phenomenon on the period 1962-1999 [23]. Differences between the dynamical systems approach and conventional signal analyses are emphasized.
Key words: time series, Earth Orientation Parameters, Takens time-delay embedding technique, ENSO phenomenon

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