DOI: 10.5194/cp-10-1659-2014
Scopus记录号: 2-s2.0-84906964868
论文题名: Dating a tropical ice core by time-frequency analysis of ion concentration depth profiles
作者: Gay M. ; De Angelis M. ; Lacoume J.-L.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 5 起始页码: 1659
结束页码: 1672
语种: 英语
Scopus关键词: concentration (composition)
; dating method
; ice core
; modeling
; nitrate
; Pleistocene
; tracking
; wavelet
; Andes
; Bolivia
; Illimani
; La Paz [Bolivia]
英文摘要: Ice core dating is a key parameter for the interpretation of the ice archives. However, the relationship between ice depth and ice age generally cannot be easily established and requires the combination of numerous investigations and/or modelling efforts. This paper presents a new approach to ice core dating based on time-frequency analysis of chemical profiles at a site where seasonal patterns may be significantly distorted by sporadic events of regional importance, specifically at the summit area of Nevado Illimani (6350 m a.s.l.), located in the eastern Bolivian Andes (16°37' S, 67°46' W). We used ion concentration depth profiles collected along a 100 m deep ice core. The results of Fourier time-frequency and wavelet transforms were first compared. Both methods were applied to a nitrate concentration depth profile. The resulting chronologies were checked by comparison with the multi-proxy year-by-year dating published by de Angelis et al. (2003) and with volcanic tie points. With this first experiment, we demonstrated the efficiency of Fourier time-frequency analysis when tracking the nitrate natural variability. In addition, we were able to show spectrum aliasing due to under-sampling below 70 m. In this article, we propose a method of de-aliasing which significantly improves the core dating in comparison with annual layer manual counting. Fourier time-frequency analysis was applied to concentration depth profiles of seven other ions, providing information on the suitability of each of them for the dating of tropical Andean ice cores. © 2014 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49227
Appears in Collections: 气候变化与战略
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Recommended Citation:
Gay M.,De Angelis M.,Lacoume J.-L.. Dating a tropical ice core by time-frequency analysis of ion concentration depth profiles[J]. Climate of the Past,2014-01-01,10(5)