Time scale evaluation and the quantification of obliquity forcing

QUATERNARY SCIENCE REVIEWS

卷:209

Article

Zeeden, Christian^1,2,3  Meyers, Stephen R.⁴  Hilgen, Frederik J.²  Lourens, Lucas J.²  Laskar, Jacques¹ 

[1] Univ Lille, UPMC Univ Paris 06, Sorbonne Univ, PSL Res Univ,IMCCE,Observ Paris,CNRS, F-75014 Paris, France

[2] Univ Utrecht, Fac Geosci, Utrecht, Netherlands

[3] LIAG, Stilleweg 2, D-30655 Hannover, Germany

[4] Univ Wisconsin, Dept Geosci, Madison, WI USA

关键词: Quaternary;    Paleoclimatology;    Data treatment;    Data analysis;    Obliquity;    Tilt;    Timescale testing;    Astrochronology;    Orbital climate forcing;   

DOI  :  10.1016/j.quascirev.2019.01.018

来源: Elsevier

【 摘 要 】

The geologic time scale serves as an essential instrument for reconstructing Earth history. Astrochronology, linking regular sedimentary alternations to theoretical quasi-periodic astronomical rhythms, often provides the highest resolution age models for strata that underlie the time scale. Although various methods for testing astronomically-tuned time scales exist, they often present challenges, such as the problem of circularity. Here, we introduce an approach to extract a reliable obliquity envelope from astronomically tuned data, avoiding the effects of frequency modulations that can artificially introduce astronomical beats. This approach includes (1) the application of a broad obliquity filter followed by (2) a Hilbert transform and (3) a low-pass filter of the amplitude envelope to (4) test the significance of correlation between amplitude envelope and astronomical solution. These data amplitudes provide a robust means to evaluate the climate response to obliquity forcing and, more specifically, to test the significance of correlation with the theoretical astronomical solution, in a manner similar to the phase randomized surrogate approach previously introduced for the evaluation of precession tuning. Synthetic astronomicalfice-sheet models and several Quaternary climate proxy records - where obliquity can be a dominant component of astronomically driven climate variability - are used to demonstrate the feasibility of the proposed method and yield new insight into climate system evolution. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

Free