New estimation of critical insolation – CO2 relationship for triggering glacial inception
It has been previously proposed that glacial inception represents a bifurcation transition between interglacial and glacial states, and is governed by the non-linear dynamics of the climate-cryosphere system. To trigger glacial inception, the orbital forcing (defined as the maximum of summer insolat...
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ftcopernicus:oai:publications.copernicus.org:cpd115043 2023-11-05T03:42:45+01:00 New estimation of critical insolation – CO2 relationship for triggering glacial inception Talento, Stefanie Willeit, Matteo Ganopolski, Andrey 2023-10-04 application/pdf https://doi.org/10.5194/cp-2023-81 https://cp.copernicus.org/preprints/cp-2023-81/ eng eng doi:10.5194/cp-2023-81 https://cp.copernicus.org/preprints/cp-2023-81/ eISSN: 1814-9332 Text 2023 ftcopernicus https://doi.org/10.5194/cp-2023-81 2023-10-09T16:24:15Z It has been previously proposed that glacial inception represents a bifurcation transition between interglacial and glacial states, and is governed by the non-linear dynamics of the climate-cryosphere system. To trigger glacial inception, the orbital forcing (defined as the maximum of summer insolation at 65° N and determined by Earth’s orbital parameters) must be lower than a critical level, which depends on the atmospheric CO 2 concentration. While paleoclimatic data do not provide a strong constraint on the dependence between CO 2 and critical insolation, its accurate estimation is of fundamental importance for predicting future glaciations and the effect that anthropogenic CO 2 emissions might have on them. In this study, we use the novel Earth system model of intermediate complexity CLIMBER-X with interactive ice sheets to produce a new estimation of the critical insolation – CO 2 relationship for triggering glacial inception. We perform a series of experiments in which different combinations of orbital forcing and atmospheric CO 2 concentration are maintained constant in time. We analyse for which combinations of orbital forcing and CO 2 glacial inception occurs and trace the critical relationship between them, separating conditions under which glacial inception is possible from those where glacial inception is not materialised. We also provide a theoretical foundation for the proposed critical insolation – CO 2 relation. We find that the use of the maximum summer insolation at 65° N as a single metric for orbital forcing is adequate for tracing the glacial inception bifurcation. Moreover, we find that the temporal and spatial patterns of ice sheet growth during glacial inception are not always the same but depend on the critical insolation and CO 2 level. The experiments evidence that during glacial inception, ice sheets grow mostly in North America, and only under low CO 2 conditions ice sheets are also formed over Scandinavia. The latter is associated with a weak Atlantic Meridional Overturning ... Text Ice Sheet Copernicus Publications: E-Journals |
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Copernicus Publications: E-Journals |
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language |
English |
description |
It has been previously proposed that glacial inception represents a bifurcation transition between interglacial and glacial states, and is governed by the non-linear dynamics of the climate-cryosphere system. To trigger glacial inception, the orbital forcing (defined as the maximum of summer insolation at 65° N and determined by Earth’s orbital parameters) must be lower than a critical level, which depends on the atmospheric CO 2 concentration. While paleoclimatic data do not provide a strong constraint on the dependence between CO 2 and critical insolation, its accurate estimation is of fundamental importance for predicting future glaciations and the effect that anthropogenic CO 2 emissions might have on them. In this study, we use the novel Earth system model of intermediate complexity CLIMBER-X with interactive ice sheets to produce a new estimation of the critical insolation – CO 2 relationship for triggering glacial inception. We perform a series of experiments in which different combinations of orbital forcing and atmospheric CO 2 concentration are maintained constant in time. We analyse for which combinations of orbital forcing and CO 2 glacial inception occurs and trace the critical relationship between them, separating conditions under which glacial inception is possible from those where glacial inception is not materialised. We also provide a theoretical foundation for the proposed critical insolation – CO 2 relation. We find that the use of the maximum summer insolation at 65° N as a single metric for orbital forcing is adequate for tracing the glacial inception bifurcation. Moreover, we find that the temporal and spatial patterns of ice sheet growth during glacial inception are not always the same but depend on the critical insolation and CO 2 level. The experiments evidence that during glacial inception, ice sheets grow mostly in North America, and only under low CO 2 conditions ice sheets are also formed over Scandinavia. The latter is associated with a weak Atlantic Meridional Overturning ... |
format |
Text |
author |
Talento, Stefanie Willeit, Matteo Ganopolski, Andrey |
spellingShingle |
Talento, Stefanie Willeit, Matteo Ganopolski, Andrey New estimation of critical insolation – CO2 relationship for triggering glacial inception |
author_facet |
Talento, Stefanie Willeit, Matteo Ganopolski, Andrey |
author_sort |
Talento, Stefanie |
title |
New estimation of critical insolation – CO2 relationship for triggering glacial inception |
title_short |
New estimation of critical insolation – CO2 relationship for triggering glacial inception |
title_full |
New estimation of critical insolation – CO2 relationship for triggering glacial inception |
title_fullStr |
New estimation of critical insolation – CO2 relationship for triggering glacial inception |
title_full_unstemmed |
New estimation of critical insolation – CO2 relationship for triggering glacial inception |
title_sort |
new estimation of critical insolation – co2 relationship for triggering glacial inception |
publishDate |
2023 |
url |
https://doi.org/10.5194/cp-2023-81 https://cp.copernicus.org/preprints/cp-2023-81/ |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-2023-81 https://cp.copernicus.org/preprints/cp-2023-81/ |
op_doi |
https://doi.org/10.5194/cp-2023-81 |
_version_ |
1781700139109318656 |