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Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record

The Dansgaard–Oeschger (DO) events, as observed in oxygen isotope ratios from the North Greenland Ice Core Project (NGRIP) record, are an outstanding example of past abrupt climate transitions. Their physical cause remains debated, and previous research indicated that they are not preceded by classi...

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Autor principal: Boers, Niklas
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6028441/
https://www.ncbi.nlm.nih.gov/pubmed/29967370
http://dx.doi.org/10.1038/s41467-018-04881-7
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author Boers, Niklas
author_facet Boers, Niklas
author_sort Boers, Niklas
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description The Dansgaard–Oeschger (DO) events, as observed in oxygen isotope ratios from the North Greenland Ice Core Project (NGRIP) record, are an outstanding example of past abrupt climate transitions. Their physical cause remains debated, and previous research indicated that they are not preceded by classical early-warning signals (EWS). Subsequent research hypothesized that the DO events are caused by bifurcations of physical mechanisms operating at decadal timescales, and proposed to search for EWS in the high-frequency fluctuation levels. Here, a time series with 5-year resolution is obtained from the raw NGRIP record, and significant numbers of EWS in terms of variance and autocorrelation increases are revealed in the decadal-scale variability. Wavelet analysis indicates that the EWS are most pronounced in the 10–50-year periodicity band, confirming the above hypothesis. The DO events are hence neither directly noise-induced nor purely externally forced, which provides valuable constraints regarding potential physical causes.
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spelling pubmed-60284412018-07-05 Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record Boers, Niklas Nat Commun Article The Dansgaard–Oeschger (DO) events, as observed in oxygen isotope ratios from the North Greenland Ice Core Project (NGRIP) record, are an outstanding example of past abrupt climate transitions. Their physical cause remains debated, and previous research indicated that they are not preceded by classical early-warning signals (EWS). Subsequent research hypothesized that the DO events are caused by bifurcations of physical mechanisms operating at decadal timescales, and proposed to search for EWS in the high-frequency fluctuation levels. Here, a time series with 5-year resolution is obtained from the raw NGRIP record, and significant numbers of EWS in terms of variance and autocorrelation increases are revealed in the decadal-scale variability. Wavelet analysis indicates that the EWS are most pronounced in the 10–50-year periodicity band, confirming the above hypothesis. The DO events are hence neither directly noise-induced nor purely externally forced, which provides valuable constraints regarding potential physical causes. Nature Publishing Group UK 2018-07-02 /pmc/articles/PMC6028441/ /pubmed/29967370 http://dx.doi.org/10.1038/s41467-018-04881-7 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Boers, Niklas
Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record
title Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record
title_full Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record
title_fullStr Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record
title_full_unstemmed Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record
title_short Early-warning signals for Dansgaard-Oeschger events in a high-resolution ice core record
title_sort early-warning signals for dansgaard-oeschger events in a high-resolution ice core record
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6028441/
https://www.ncbi.nlm.nih.gov/pubmed/29967370
http://dx.doi.org/10.1038/s41467-018-04881-7
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