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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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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Nature Publishing Group UK
2018
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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 |
collection | PubMed |
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. |
format | Online Article Text |
id | pubmed-6028441 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
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 |
work_keys_str_mv | AT boersniklas earlywarningsignalsfordansgaardoeschgereventsinahighresolutionicecorerecord |