Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies
Different paleoclimate proxy records evidence repeated abrupt climate transitions during previous glacial intervals. These transitions are thought to comprise abrupt warming and increase in local precipitation over Greenland, sudden reorganization of the Northern Hemisphere atmospheric circulation,...
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ftdatacite:10.17169/refubium-32201 2023-05-15T16:27:18+02:00 Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies Riechers, Keno Boers, Niklas 2021 https://dx.doi.org/10.17169/refubium-32201 https://refubium.fu-berlin.de/handle/fub188/32476 unknown Freie Universität Berlin https://doi.org/10.5194/cp-17-1751-2021 https://dx.doi.org/10.5194/cp-17-1751-2021 https://doi.org/10.5194/cp-17-1751-2021 Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY paleoclimate proxy records abrupt climate transitions glacial intervals 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften Wissenschaftlicher Artikel article-journal Text ScholarlyArticle 2021 ftdatacite https://doi.org/10.17169/refubium-32201 https://doi.org/10.5194/cp-17-1751-2021 2022-02-08T12:27:12Z Different paleoclimate proxy records evidence repeated abrupt climate transitions during previous glacial intervals. These transitions are thought to comprise abrupt warming and increase in local precipitation over Greenland, sudden reorganization of the Northern Hemisphere atmospheric circulation, and retreat of sea ice in the North Atlantic. The physical mechanism underlying these so-called Dansgaard–Oeschger (DO) events remains debated. A recent analysis of Greenland ice core proxy records found that transitions in Na+ concentrations and δ18O values are delayed by about 1 decade with respect to corresponding transitions in Ca2+ concentrations and in the annual layer thickness during DO events. These delays are interpreted as a temporal lag of sea-ice retreat and Greenland warming with respect to a synoptic- and hemispheric-scale atmospheric reorganization at the onset of DO events and may thereby help constrain possible triggering mechanisms for the DO events. However, the explanatory power of these results is limited by the uncertainty of the transition onset detection in noisy proxy records. Here, we extend previous work by testing the significance of the reported lags with respect to the null hypothesis that the proposed transition order is in fact not systematically favored. If the detection uncertainties are averaged out, the temporal delays in the δ18O and Na+ transitions with respect to their counterparts in Ca2+ and the annual layer thickness are indeed pairwise statistically significant. In contrast, under rigorous propagation of uncertainty, three statistical tests cannot provide evidence against the null hypothesis. We thus confirm the previously reported tendency of delayed transitions in the δ18O and Na+ concentration records. Yet, given the uncertainties in the determination of the transition onsets, it cannot be decided whether these tendencies are truly the imprint of a prescribed transition order or whether they are due to chance. The analyzed set of DO transitions can therefore not serve as evidence for systematic lead–lag relationships between the transitions in the different proxies, which in turn limits the power of the observed tendencies to constrain possible physical causes of the DO events. Text Greenland Greenland ice core ice core North Atlantic Sea ice DataCite Metadata Store (German National Library of Science and Technology) Greenland |
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Open Polar |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
paleoclimate proxy records abrupt climate transitions glacial intervals 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften |
spellingShingle |
paleoclimate proxy records abrupt climate transitions glacial intervals 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften Riechers, Keno Boers, Niklas Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies |
topic_facet |
paleoclimate proxy records abrupt climate transitions glacial intervals 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften |
description |
Different paleoclimate proxy records evidence repeated abrupt climate transitions during previous glacial intervals. These transitions are thought to comprise abrupt warming and increase in local precipitation over Greenland, sudden reorganization of the Northern Hemisphere atmospheric circulation, and retreat of sea ice in the North Atlantic. The physical mechanism underlying these so-called Dansgaard–Oeschger (DO) events remains debated. A recent analysis of Greenland ice core proxy records found that transitions in Na+ concentrations and δ18O values are delayed by about 1 decade with respect to corresponding transitions in Ca2+ concentrations and in the annual layer thickness during DO events. These delays are interpreted as a temporal lag of sea-ice retreat and Greenland warming with respect to a synoptic- and hemispheric-scale atmospheric reorganization at the onset of DO events and may thereby help constrain possible triggering mechanisms for the DO events. However, the explanatory power of these results is limited by the uncertainty of the transition onset detection in noisy proxy records. Here, we extend previous work by testing the significance of the reported lags with respect to the null hypothesis that the proposed transition order is in fact not systematically favored. If the detection uncertainties are averaged out, the temporal delays in the δ18O and Na+ transitions with respect to their counterparts in Ca2+ and the annual layer thickness are indeed pairwise statistically significant. In contrast, under rigorous propagation of uncertainty, three statistical tests cannot provide evidence against the null hypothesis. We thus confirm the previously reported tendency of delayed transitions in the δ18O and Na+ concentration records. Yet, given the uncertainties in the determination of the transition onsets, it cannot be decided whether these tendencies are truly the imprint of a prescribed transition order or whether they are due to chance. The analyzed set of DO transitions can therefore not serve as evidence for systematic lead–lag relationships between the transitions in the different proxies, which in turn limits the power of the observed tendencies to constrain possible physical causes of the DO events. |
format |
Text |
author |
Riechers, Keno Boers, Niklas |
author_facet |
Riechers, Keno Boers, Niklas |
author_sort |
Riechers, Keno |
title |
Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies |
title_short |
Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies |
title_full |
Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies |
title_fullStr |
Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies |
title_full_unstemmed |
Significance of uncertain phasing between the onsets of stadial–interstadial transitions in different Greenland ice core proxies |
title_sort |
significance of uncertain phasing between the onsets of stadial–interstadial transitions in different greenland ice core proxies |
publisher |
Freie Universität Berlin |
publishDate |
2021 |
url |
https://dx.doi.org/10.17169/refubium-32201 https://refubium.fu-berlin.de/handle/fub188/32476 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland ice core ice core North Atlantic Sea ice |
genre_facet |
Greenland Greenland ice core ice core North Atlantic Sea ice |
op_relation |
https://doi.org/10.5194/cp-17-1751-2021 https://dx.doi.org/10.5194/cp-17-1751-2021 https://doi.org/10.5194/cp-17-1751-2021 |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.17169/refubium-32201 https://doi.org/10.5194/cp-17-1751-2021 |
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1766016438240280576 |