Orbital forcings of the Earth?s climate in wavelet domain
International audience We examine two paleoclimate proxy records ? the temperature differences from the Antarctic Vostok ice core and the composite ? 18 O 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-deci...
Main Authors: | , , , , |
---|---|
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2005
|
Subjects: | |
Online Access: | https://hal.science/hal-00298116 https://hal.science/hal-00298116/document https://hal.science/hal-00298116/file/cpd-1-193-2005.pdf |
Summary: | International audience We examine two paleoclimate proxy records ? the temperature differences from the Antarctic Vostok ice core and the composite ? 18 O 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 ? 18 O. Since the ~1.7 million years BP, minor and significant maxima alternated and this not affected as much the variations of ? 18 O. |
---|