Status: this preprint was under review for the journal CP but the revision was not accepted.
Orbital forcings of the Earth’s climate in wavelet domain
A. V. Glushkov,V. N. Khokhlov,N. S. Loboda,V. D. Rusov,and V. N. Vaschenko
A. V. Glushkov
Institute for Applied Mathematics, Department of Computational Mathematics, Odessa, Ukraine
V. N. Khokhlov
Innovative Geosciences Research Centre, Department of Hydrometeorology, Odessa, Ukraine
N. S. Loboda
Innovative Geosciences Research Centre, Department of Hydrometeorology, Odessa, Ukraine
V. D. Rusov
Odessa National Polytechnic University, Department of Theoretical Physics, Odessa, Ukraine
V. N. Vaschenko
Kiev National University, Department of Antarctic Sciences, Kiev, Ukraine
Abstract. We examine two paleoclimate proxy records – the temperature differences from the Antarctic Vostok ice core and the composite δ18O record from three sites (V19-30, ODP 677, and ODP 846) – in order to search for indications of orbital forcings. We demonstrate that the non-decimated wavelet transform is an appropriate tool for investigating temporarily changing spectral properties of records. Our results indicate that abrupt climate warmings with cyclicity of ~100 kiloyears during the last 400 kiloyears were caused by the combined unidirectional influences of three orbital parameters and the eccentricity can be considered as a modulator defining transitions from the Ice Ages to the periods of comparative warmings. Non-decimated wavelet transform avails discovering the possible part played in climate change by the eccentricity-forced variations. Up to approximately 1.7 million years BP, the influence of this variations of eccentricity appears in increasing for almost all local maxima of δ18O. Since the ~1.7 million years BP, minor and significant maxima alternated and this not affected as much the variations of δ18O.
Received: 03 Aug 2005 – Discussion started: 23 Sep 2005