Abrupt climate change: an alternative view
Hypotheses and inferences concerning the nature of abrupt climate change, exemplified by the Dansgaard-Oeschger (D-O) events, are reviewed. There is little concrete evidence that these events are more than a regional Greenland phenomenon. The partial coherence of ice core δ18OandCH4is a possible exc...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.395.2056 2023-05-15T16:13:02+02:00 Abrupt climate change: an alternative view Carl Wunsch The Pennsylvania State University CiteSeerX Archives 2006 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.2056 http://ocean.mit.edu/~cwunsch/papersonline/doevents.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.2056 http://ocean.mit.edu/~cwunsch/papersonline/doevents.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://ocean.mit.edu/~cwunsch/papersonline/doevents.pdf text 2006 ftciteseerx 2016-01-08T02:26:27Z Hypotheses and inferences concerning the nature of abrupt climate change, exemplified by the Dansgaard-Oeschger (D-O) events, are reviewed. There is little concrete evidence that these events are more than a regional Greenland phenomenon. The partial coherence of ice core δ18OandCH4is a possible exception. Claims, however, of D-O presence in most remote locations cannot be distinguished from the hypothesis that many regions are just exhibiting temporal variability in climate proxies with approximately similar frequency content. Further suggestions that D-O events in Greenland are a generated by shifts in the North Atlantic ocean circulation seem highly implausible, given the weak contribution of the high latitude ocean to the meridional flux of heat. A more likely scenario is that changes in the ocean circulation are a consequence of wind shifts. The disappearance of D-O events in the Holocene coincides with the disappearance also of the Laurentide and Fennoscandian ice sheets. It is thus suggested that D-O events are a consequence of interactions of the windfield with the continental ice sheets and that better understanding of the windfield in the glacial periods is the highest priority. Wind fields are capable of great volatility, very rapid global-scale teleconnections, are efficient generators of oceanic circulation changes and (more speculatively) of multiple states relative to great ice sheets. Connection of D-O events to the possibility of modern abrupt climate change rests on a very weak chain of assumptions. 1 Text Fennoscandian Greenland ice core North Atlantic Unknown Greenland |
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English |
description |
Hypotheses and inferences concerning the nature of abrupt climate change, exemplified by the Dansgaard-Oeschger (D-O) events, are reviewed. There is little concrete evidence that these events are more than a regional Greenland phenomenon. The partial coherence of ice core δ18OandCH4is a possible exception. Claims, however, of D-O presence in most remote locations cannot be distinguished from the hypothesis that many regions are just exhibiting temporal variability in climate proxies with approximately similar frequency content. Further suggestions that D-O events in Greenland are a generated by shifts in the North Atlantic ocean circulation seem highly implausible, given the weak contribution of the high latitude ocean to the meridional flux of heat. A more likely scenario is that changes in the ocean circulation are a consequence of wind shifts. The disappearance of D-O events in the Holocene coincides with the disappearance also of the Laurentide and Fennoscandian ice sheets. It is thus suggested that D-O events are a consequence of interactions of the windfield with the continental ice sheets and that better understanding of the windfield in the glacial periods is the highest priority. Wind fields are capable of great volatility, very rapid global-scale teleconnections, are efficient generators of oceanic circulation changes and (more speculatively) of multiple states relative to great ice sheets. Connection of D-O events to the possibility of modern abrupt climate change rests on a very weak chain of assumptions. 1 |
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The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Carl Wunsch |
spellingShingle |
Carl Wunsch Abrupt climate change: an alternative view |
author_facet |
Carl Wunsch |
author_sort |
Carl Wunsch |
title |
Abrupt climate change: an alternative view |
title_short |
Abrupt climate change: an alternative view |
title_full |
Abrupt climate change: an alternative view |
title_fullStr |
Abrupt climate change: an alternative view |
title_full_unstemmed |
Abrupt climate change: an alternative view |
title_sort |
abrupt climate change: an alternative view |
publishDate |
2006 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.2056 http://ocean.mit.edu/~cwunsch/papersonline/doevents.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Fennoscandian Greenland ice core North Atlantic |
genre_facet |
Fennoscandian Greenland ice core North Atlantic |
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http://ocean.mit.edu/~cwunsch/papersonline/doevents.pdf |
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http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.2056 http://ocean.mit.edu/~cwunsch/papersonline/doevents.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1765998642724864000 |