NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE
Periods of abrupt climate cooling during the last deglaciation (20,000-8,000 yrs ago) are often attributed to glacial outburst floods slowing the Atlantic meridional overturning circulation (AMOC). Yet, despite over 40 years of research, conclusive evidence that such events significantly impact clim...
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ftdatacite:10.7275/14896019 2023-05-15T14:45:35+02:00 NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE Joyce, Anthony J 2019 https://dx.doi.org/10.7275/14896019 https://scholarworks.umass.edu/dissertations_2/1685 unknown University of Massachusetts Amherst Thesis Text Dissertation thesis 2019 ftdatacite https://doi.org/10.7275/14896019 2021-11-05T12:55:41Z Periods of abrupt climate cooling during the last deglaciation (20,000-8,000 yrs ago) are often attributed to glacial outburst floods slowing the Atlantic meridional overturning circulation (AMOC). Yet, despite over 40 years of research, conclusive evidence that such events significantly impact climate remains elusive. This study uses a climate model to investigate an alternative freshwater forcing mechanism in which the episodic break-up and mobilization of thick perennial Arctic sea ice might have disrupted large-scale climate. The results presented here show the first evidence that (1) the Arctic Ocean stored enormous volumes of freshwater during colder periods as thick masses of sea ice, and (2) that massive sea ice export events to the North Atlantic are generated whenever the transport of sea ice is enhanced either by changes in atmospheric circulation, rising sea level submerging the Bering land bridge, or glacial outburst floods draining into the Arctic Ocean from the Mackenzie River. Of relevance for understanding the key drivers of past abrupt climate change, I found that the volumes of freshwater released to the Nordic Seas are similar to, or larger than, those estimated to have come from terrestrial outburst floods, including a discharge around 12,900 years ago that is often considered the cause of the Younger Dryas cooling. The results from my thesis thus provide the first evidence that the storage and release of Arctic sea ice helped modulate deglacial climate change. Thesis Arctic Arctic Ocean Bering Land Bridge Climate change Mackenzie river Nordic Seas North Atlantic Sea ice DataCite Metadata Store (German National Library of Science and Technology) Arctic Arctic Ocean Mackenzie River |
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Periods of abrupt climate cooling during the last deglaciation (20,000-8,000 yrs ago) are often attributed to glacial outburst floods slowing the Atlantic meridional overturning circulation (AMOC). Yet, despite over 40 years of research, conclusive evidence that such events significantly impact climate remains elusive. This study uses a climate model to investigate an alternative freshwater forcing mechanism in which the episodic break-up and mobilization of thick perennial Arctic sea ice might have disrupted large-scale climate. The results presented here show the first evidence that (1) the Arctic Ocean stored enormous volumes of freshwater during colder periods as thick masses of sea ice, and (2) that massive sea ice export events to the North Atlantic are generated whenever the transport of sea ice is enhanced either by changes in atmospheric circulation, rising sea level submerging the Bering land bridge, or glacial outburst floods draining into the Arctic Ocean from the Mackenzie River. Of relevance for understanding the key drivers of past abrupt climate change, I found that the volumes of freshwater released to the Nordic Seas are similar to, or larger than, those estimated to have come from terrestrial outburst floods, including a discharge around 12,900 years ago that is often considered the cause of the Younger Dryas cooling. The results from my thesis thus provide the first evidence that the storage and release of Arctic sea ice helped modulate deglacial climate change. |
format |
Thesis |
author |
Joyce, Anthony J |
spellingShingle |
Joyce, Anthony J NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE |
author_facet |
Joyce, Anthony J |
author_sort |
Joyce, Anthony J |
title |
NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE |
title_short |
NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE |
title_full |
NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE |
title_fullStr |
NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE |
title_full_unstemmed |
NUMERICAL CLIMATE MODEL SIMULATIONS INVESTIGATING THE ROLE OF ARCTIC SEA ICE EXPORT EVENTS IN MODULATING DEGLACIAL CLIMATE |
title_sort |
numerical climate model simulations investigating the role of arctic sea ice export events in modulating deglacial climate |
publisher |
University of Massachusetts Amherst |
publishDate |
2019 |
url |
https://dx.doi.org/10.7275/14896019 https://scholarworks.umass.edu/dissertations_2/1685 |
geographic |
Arctic Arctic Ocean Mackenzie River |
geographic_facet |
Arctic Arctic Ocean Mackenzie River |
genre |
Arctic Arctic Ocean Bering Land Bridge Climate change Mackenzie river Nordic Seas North Atlantic Sea ice |
genre_facet |
Arctic Arctic Ocean Bering Land Bridge Climate change Mackenzie river Nordic Seas North Atlantic Sea ice |
op_doi |
https://doi.org/10.7275/14896019 |
_version_ |
1766316978461474816 |