A theory of abrupt climate changes: their genesis and anatomy
We integrate our previous ice-sheet and climate models to examine abrupt climate changes pertaining to Heinrich event (HE), Dansgaard-Oeschger (DO) cycle as well as last deglaciation punctuated by Younger Dryas (YD). Since they are all accompanied by ice-rafted debris, we posit their common origin i...
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00060965 2023-05-15T16:35:30+02:00 A theory of abrupt climate changes: their genesis and anatomy Ou, Hsien-Wang 2022-05 electronic https://doi.org/10.5194/egusphere-2022-208 https://noa.gwlb.de/receive/cop_mods_00060965 https://egusphere.copernicus.org/preprints/egusphere-2022-208/egusphere-2022-208.pdf eng eng Copernicus Publications https://doi.org/10.5194/egusphere-2022-208 https://noa.gwlb.de/receive/cop_mods_00060965 https://egusphere.copernicus.org/preprints/egusphere-2022-208/egusphere-2022-208.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/restrictedAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/egusphere-2022-208 2022-05-15T23:09:49Z We integrate our previous ice-sheet and climate models to examine abrupt climate changes pertaining to Heinrich event (HE), Dansgaard-Oeschger (DO) cycle as well as last deglaciation punctuated by Younger Dryas (YD). Since they are all accompanied by ice-rafted debris, we posit their common origin in the calving of ice sheet due to thermal switch at its bed. Such thermal switch would generate step-like freshwater flux and together with decadal ocean response, they would endow abruptness to these millennial climate signals, which need not involve ocean mode change, as commonly assumed. We distinguish thermal switches due to geothermal heat and surface melt, which would calve inland/marginal ice to drive HE/DO-cycle, respectively. As such, the glacial DO-cycle hinges on post-HE warmth that enables the ablation whereas the Holocene DO-cycle is self-sustaining. The ocean response to freshwater flux entails millennial adjustment to maximum entropy production (MEP), a process termed “MEP adjustment”. As its direct consequence, the termination of HE is accompanied by sudden warming followed by gradual cooling to exhibit saw-toothed H-cycle, and the cooling moreover would anchor DO-cycles to form the hierarchical Bond cycle. The meltwater produced during deglaciation, if rerouted to Hudson Bay, may augment the calving-induced freshwater flux to cause YD, the latter thus involves happenstance and did not materialize during penultimate deglaciation. By incorporating calving origin of the freshwater flux and MEP adjustment of the ocean, the theory has provided an integral account of these abrupt climate changes. Article in Journal/Newspaper Hudson Bay Ice Sheet Niedersächsisches Online-Archiv NOA Hudson Hudson Bay |
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Niedersächsisches Online-Archiv NOA |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Ou, Hsien-Wang A theory of abrupt climate changes: their genesis and anatomy |
topic_facet |
article Verlagsveröffentlichung |
description |
We integrate our previous ice-sheet and climate models to examine abrupt climate changes pertaining to Heinrich event (HE), Dansgaard-Oeschger (DO) cycle as well as last deglaciation punctuated by Younger Dryas (YD). Since they are all accompanied by ice-rafted debris, we posit their common origin in the calving of ice sheet due to thermal switch at its bed. Such thermal switch would generate step-like freshwater flux and together with decadal ocean response, they would endow abruptness to these millennial climate signals, which need not involve ocean mode change, as commonly assumed. We distinguish thermal switches due to geothermal heat and surface melt, which would calve inland/marginal ice to drive HE/DO-cycle, respectively. As such, the glacial DO-cycle hinges on post-HE warmth that enables the ablation whereas the Holocene DO-cycle is self-sustaining. The ocean response to freshwater flux entails millennial adjustment to maximum entropy production (MEP), a process termed “MEP adjustment”. As its direct consequence, the termination of HE is accompanied by sudden warming followed by gradual cooling to exhibit saw-toothed H-cycle, and the cooling moreover would anchor DO-cycles to form the hierarchical Bond cycle. The meltwater produced during deglaciation, if rerouted to Hudson Bay, may augment the calving-induced freshwater flux to cause YD, the latter thus involves happenstance and did not materialize during penultimate deglaciation. By incorporating calving origin of the freshwater flux and MEP adjustment of the ocean, the theory has provided an integral account of these abrupt climate changes. |
format |
Article in Journal/Newspaper |
author |
Ou, Hsien-Wang |
author_facet |
Ou, Hsien-Wang |
author_sort |
Ou, Hsien-Wang |
title |
A theory of abrupt climate changes: their genesis and anatomy |
title_short |
A theory of abrupt climate changes: their genesis and anatomy |
title_full |
A theory of abrupt climate changes: their genesis and anatomy |
title_fullStr |
A theory of abrupt climate changes: their genesis and anatomy |
title_full_unstemmed |
A theory of abrupt climate changes: their genesis and anatomy |
title_sort |
theory of abrupt climate changes: their genesis and anatomy |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/egusphere-2022-208 https://noa.gwlb.de/receive/cop_mods_00060965 https://egusphere.copernicus.org/preprints/egusphere-2022-208/egusphere-2022-208.pdf |
geographic |
Hudson Hudson Bay |
geographic_facet |
Hudson Hudson Bay |
genre |
Hudson Bay Ice Sheet |
genre_facet |
Hudson Bay Ice Sheet |
op_relation |
https://doi.org/10.5194/egusphere-2022-208 https://noa.gwlb.de/receive/cop_mods_00060965 https://egusphere.copernicus.org/preprints/egusphere-2022-208/egusphere-2022-208.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/restrictedAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/egusphere-2022-208 |
_version_ |
1766025733317066752 |