Limitations of red noise in analysing Dansgaard-Oeschger events
During the last glacial period, climate records from the North Atlantic region exhibit a pronounced spectral component corresponding to a period of about 1470 years, which has attracted much attention. This spectral peak is closely related to the recurrence pattern of Dansgaard-Oeschger (DO) events....
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ftcopernicus:oai:publications.copernicus.org:cp1219 2023-05-15T16:00:02+02:00 Limitations of red noise in analysing Dansgaard-Oeschger events Braun, H. Ditlevsen, P. Kurths, J. Mudelsee, M. 2018-09-27 application/pdf https://doi.org/10.5194/cp-6-85-2010 https://cp.copernicus.org/articles/6/85/2010/ eng eng doi:10.5194/cp-6-85-2010 https://cp.copernicus.org/articles/6/85/2010/ eISSN: 1814-9332 Text 2018 ftcopernicus https://doi.org/10.5194/cp-6-85-2010 2020-07-20T16:26:28Z During the last glacial period, climate records from the North Atlantic region exhibit a pronounced spectral component corresponding to a period of about 1470 years, which has attracted much attention. This spectral peak is closely related to the recurrence pattern of Dansgaard-Oeschger (DO) events. In previous studies a red noise random process, more precisely a first-order autoregressive (AR1) process, was used to evaluate the statistical significance of this peak, with a reported significance of more than 99%. Here we use a simple mechanistic two-state model of DO events, which itself was derived from a much more sophisticated ocean-atmosphere model of intermediate complexity, to numerically evaluate the spectral properties of random (i.e., solely noise-driven) events. This way we find that the power spectral density of random DO events differs fundamentally from a simple red noise random process. These results question the applicability of linear spectral analysis for estimating the statistical significance of highly non-linear processes such as DO events. More precisely, to enhance our scientific understanding about the trigger of DO events, we must not consider simple "straw men" as, for example, the AR1 random process, but rather test against realistic alternative descriptions. Text Dansgaard-Oeschger events North Atlantic Copernicus Publications: E-Journals Climate of the Past 6 1 85 92 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
During the last glacial period, climate records from the North Atlantic region exhibit a pronounced spectral component corresponding to a period of about 1470 years, which has attracted much attention. This spectral peak is closely related to the recurrence pattern of Dansgaard-Oeschger (DO) events. In previous studies a red noise random process, more precisely a first-order autoregressive (AR1) process, was used to evaluate the statistical significance of this peak, with a reported significance of more than 99%. Here we use a simple mechanistic two-state model of DO events, which itself was derived from a much more sophisticated ocean-atmosphere model of intermediate complexity, to numerically evaluate the spectral properties of random (i.e., solely noise-driven) events. This way we find that the power spectral density of random DO events differs fundamentally from a simple red noise random process. These results question the applicability of linear spectral analysis for estimating the statistical significance of highly non-linear processes such as DO events. More precisely, to enhance our scientific understanding about the trigger of DO events, we must not consider simple "straw men" as, for example, the AR1 random process, but rather test against realistic alternative descriptions. |
format |
Text |
author |
Braun, H. Ditlevsen, P. Kurths, J. Mudelsee, M. |
spellingShingle |
Braun, H. Ditlevsen, P. Kurths, J. Mudelsee, M. Limitations of red noise in analysing Dansgaard-Oeschger events |
author_facet |
Braun, H. Ditlevsen, P. Kurths, J. Mudelsee, M. |
author_sort |
Braun, H. |
title |
Limitations of red noise in analysing Dansgaard-Oeschger events |
title_short |
Limitations of red noise in analysing Dansgaard-Oeschger events |
title_full |
Limitations of red noise in analysing Dansgaard-Oeschger events |
title_fullStr |
Limitations of red noise in analysing Dansgaard-Oeschger events |
title_full_unstemmed |
Limitations of red noise in analysing Dansgaard-Oeschger events |
title_sort |
limitations of red noise in analysing dansgaard-oeschger events |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-6-85-2010 https://cp.copernicus.org/articles/6/85/2010/ |
genre |
Dansgaard-Oeschger events North Atlantic |
genre_facet |
Dansgaard-Oeschger events North Atlantic |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-6-85-2010 https://cp.copernicus.org/articles/6/85/2010/ |
op_doi |
https://doi.org/10.5194/cp-6-85-2010 |
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Climate of the Past |
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6 |
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1 |
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85 |
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92 |
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1766395912238661632 |