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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ftleibnizopen:oai:oai.leibnizopen.de:sJNS04kBdbrxVwz6ahVj 2023-10-01T03:55:37+02:00 A simple conceptual model of abrupt glacial climate events Braun, H. Ganopolski, A. Christl, M. Chialvo, D.R. 2007 application/pdf https://oa.tib.eu/renate/handle/123456789/5342 https://doi.org/10.34657/3971 eng eng Göttingen : Copernicus GmbH CC BY-NC-SA 2.5 Unported https://creativecommons.org/licenses/by-nc-sa/2.5/ Nonlinear Processes in Geophysics 14 (2007), Nr. 6 climate change Dansgaard-Oeschger cycle deep water Earth glacial environment nonlinearity stochasticity Atlantic Ocean Atlantic Ocean (North) 550 article Text 2007 ftleibnizopen https://doi.org/10.34657/3971 2023-09-03T23:38:48Z 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. publishedVersion Article in Journal/Newspaper Dansgaard-Oeschger events North Atlantic LeibnizOpen (The Leibniz Association) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
climate change Dansgaard-Oeschger cycle deep water Earth glacial environment nonlinearity stochasticity Atlantic Ocean Atlantic Ocean (North) 550 |
spellingShingle |
climate change Dansgaard-Oeschger cycle deep water Earth glacial environment nonlinearity stochasticity Atlantic Ocean Atlantic Ocean (North) 550 Braun, H. Ganopolski, A. Christl, M. Chialvo, D.R. A simple conceptual model of abrupt glacial climate events |
topic_facet |
climate change Dansgaard-Oeschger cycle deep water Earth glacial environment nonlinearity stochasticity Atlantic Ocean Atlantic Ocean (North) 550 |
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. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Braun, H. Ganopolski, A. Christl, M. Chialvo, D.R. |
author_facet |
Braun, H. Ganopolski, A. Christl, M. Chialvo, D.R. |
author_sort |
Braun, H. |
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 |
Göttingen : Copernicus GmbH |
publishDate |
2007 |
url |
https://oa.tib.eu/renate/handle/123456789/5342 https://doi.org/10.34657/3971 |
genre |
Dansgaard-Oeschger events North Atlantic |
genre_facet |
Dansgaard-Oeschger events North Atlantic |
op_source |
Nonlinear Processes in Geophysics 14 (2007), Nr. 6 |
op_rights |
CC BY-NC-SA 2.5 Unported https://creativecommons.org/licenses/by-nc-sa/2.5/ |
op_doi |
https://doi.org/10.34657/3971 |
_version_ |
1778524188535947264 |