A simple conceptual model of abrupt glacial climate events
Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events) to a few simple principles, namely (i) the existence of two different climate states, (ii) a threshold process an...
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ftdoajarticles:oai:doaj.org/article:6634391e9012473f820b9dc0bec81699 2023-05-15T15:59:59+02:00 A simple conceptual model of abrupt glacial climate events H. Braun A. Ganopolski M. Christl D. R. Chialvo 2007-11-01T00:00:00Z https://doaj.org/article/6634391e9012473f820b9dc0bec81699 EN eng Copernicus Publications http://www.nonlin-processes-geophys.net/14/709/2007/npg-14-709-2007.pdf https://doaj.org/toc/1023-5809 https://doaj.org/toc/1607-7946 1023-5809 1607-7946 https://doaj.org/article/6634391e9012473f820b9dc0bec81699 Nonlinear Processes in Geophysics, Vol 14, Iss 6, Pp 709-721 (2007) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2007 ftdoajarticles 2023-01-08T01:33:02Z Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events) to a few simple principles, namely (i) the existence of two different climate states, (ii) a threshold process and (iii) an overshooting in the stability of the system at the start and the end of the events, which is followed by a millennial-scale relaxation. By comparison with a so-called Earth system model of intermediate complexity (CLIMBER-2), in which the events represent oscillations between two climate states corresponding to two fundamentally different modes of deep-water formation in the North Atlantic, we demonstrate that the conceptual model captures fundamental aspects of the nonlinearity of the events in that model. We use the conceptual model in order to reproduce and reanalyse nonlinear resonance mechanisms that were already suggested in order to explain the characteristic time scale of Dansgaard-Oeschger events. In doing so we identify a new form of stochastic resonance (i.e. an overshooting stochastic resonance ) and provide the first explicitly reported manifestation of ghost resonance in a geosystem, i.e. of a mechanism which could be relevant for other systems with thresholds and with multiple states of operation. Our work enables us to explicitly simulate realistic probability measures of Dansgaard-Oeschger events (e.g. waiting time distributions, which are a prerequisite for statistical analyses on the regularity of the events by means of Monte-Carlo simulations). We thus think that our study is an important advance in order to develop more adequate methods to test the statistical significance and the origin of the proposed glacial 1470-year climate cycle. Article in Journal/Newspaper Dansgaard-Oeschger events North Atlantic Directory of Open Access Journals: DOAJ Articles |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
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language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 H. Braun A. Ganopolski M. Christl D. R. Chialvo A simple conceptual model of abrupt glacial climate events |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events) to a few simple principles, namely (i) the existence of two different climate states, (ii) a threshold process and (iii) an overshooting in the stability of the system at the start and the end of the events, which is followed by a millennial-scale relaxation. By comparison with a so-called Earth system model of intermediate complexity (CLIMBER-2), in which the events represent oscillations between two climate states corresponding to two fundamentally different modes of deep-water formation in the North Atlantic, we demonstrate that the conceptual model captures fundamental aspects of the nonlinearity of the events in that model. We use the conceptual model in order to reproduce and reanalyse nonlinear resonance mechanisms that were already suggested in order to explain the characteristic time scale of Dansgaard-Oeschger events. In doing so we identify a new form of stochastic resonance (i.e. an overshooting stochastic resonance ) and provide the first explicitly reported manifestation of ghost resonance in a geosystem, i.e. of a mechanism which could be relevant for other systems with thresholds and with multiple states of operation. Our work enables us to explicitly simulate realistic probability measures of Dansgaard-Oeschger events (e.g. waiting time distributions, which are a prerequisite for statistical analyses on the regularity of the events by means of Monte-Carlo simulations). We thus think that our study is an important advance in order to develop more adequate methods to test the statistical significance and the origin of the proposed glacial 1470-year climate cycle. |
format |
Article in Journal/Newspaper |
author |
H. Braun A. Ganopolski M. Christl D. R. Chialvo |
author_facet |
H. Braun A. Ganopolski M. Christl D. R. Chialvo |
author_sort |
H. Braun |
title |
A simple conceptual model of abrupt glacial climate events |
title_short |
A simple conceptual model of abrupt glacial climate events |
title_full |
A simple conceptual model of abrupt glacial climate events |
title_fullStr |
A simple conceptual model of abrupt glacial climate events |
title_full_unstemmed |
A simple conceptual model of abrupt glacial climate events |
title_sort |
simple conceptual model of abrupt glacial climate events |
publisher |
Copernicus Publications |
publishDate |
2007 |
url |
https://doaj.org/article/6634391e9012473f820b9dc0bec81699 |
genre |
Dansgaard-Oeschger events North Atlantic |
genre_facet |
Dansgaard-Oeschger events North Atlantic |
op_source |
Nonlinear Processes in Geophysics, Vol 14, Iss 6, Pp 709-721 (2007) |
op_relation |
http://www.nonlin-processes-geophys.net/14/709/2007/npg-14-709-2007.pdf https://doaj.org/toc/1023-5809 https://doaj.org/toc/1607-7946 1023-5809 1607-7946 https://doaj.org/article/6634391e9012473f820b9dc0bec81699 |
_version_ |
1766395866959052800 |