North Pacific seasonality and the glaciation of North America 2.7 million years ago
In the context of gradual Cenozoic cooling, the timing of the onset of significant Northern Hemisphere glaciation 2.7 million years ago is consistent with Milankovitch's orbital theory, which posited that ice sheets grow when polar summertime insolation and temperature are low. However, the rol...
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NATURE PUBLISHING GROUP
2005
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ftucl:oai:eprints.ucl.ac.uk.OAI2:182640 2023-05-15T15:06:16+02:00 North Pacific seasonality and the glaciation of North America 2.7 million years ago Haug, GH Ganopolski, A Sigman, DM Rosell-Mele, A Swann, GEA Tiedemann, R Jaccard, SL Bollmann, J Maslin, MA Leng, MJ Eglinton, G 2005-02-24 http://discovery.ucl.ac.uk/182640/ unknown NATURE PUBLISHING GROUP NATURE , 433 (7028) 821 - 825. (2005) SUB-ARCTIC PACIFIC THERMOHALINE CIRCULATION INTERMEDIATE COMPLEXITY OCEAN CLIMATE ATLANTIC CALIBRATION STRATIFICATION RECORDS SILICA Article 2005 ftucl 2013-11-10T03:12:23Z In the context of gradual Cenozoic cooling, the timing of the onset of significant Northern Hemisphere glaciation 2.7 million years ago is consistent with Milankovitch's orbital theory, which posited that ice sheets grow when polar summertime insolation and temperature are low. However, the role of moisture supply in the initiation of large Northern Hemisphere ice sheets has remained unclear. The subarctic Pacific Ocean represents a significant source of water vapour to boreal North America, but it has been largely overlooked in efforts to explain Northern Hemisphere glaciation. Here we present alkenone unsaturation ratios and diatom oxygen isotope ratios from a sediment core in the western subarctic Pacific Ocean, indicating that 2.7 million years ago late-summer sea surface temperatures in this ocean region rose in response to an increase in stratification. At the same time, winter sea surface temperatures cooled, winter floating ice became more abundant and global climate descended into glacial conditions. We suggest that the observed summer warming extended into the autumn, providing water vapour to northern North America, where it precipitated and accumulated as snow, and thus allowed the initiation of Northern Hemisphere glaciation. Article in Journal/Newspaper Arctic Subarctic University College London: UCL Discovery Arctic Pacific |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
unknown |
topic |
SUB-ARCTIC PACIFIC THERMOHALINE CIRCULATION INTERMEDIATE COMPLEXITY OCEAN CLIMATE ATLANTIC CALIBRATION STRATIFICATION RECORDS SILICA |
spellingShingle |
SUB-ARCTIC PACIFIC THERMOHALINE CIRCULATION INTERMEDIATE COMPLEXITY OCEAN CLIMATE ATLANTIC CALIBRATION STRATIFICATION RECORDS SILICA Haug, GH Ganopolski, A Sigman, DM Rosell-Mele, A Swann, GEA Tiedemann, R Jaccard, SL Bollmann, J Maslin, MA Leng, MJ Eglinton, G North Pacific seasonality and the glaciation of North America 2.7 million years ago |
topic_facet |
SUB-ARCTIC PACIFIC THERMOHALINE CIRCULATION INTERMEDIATE COMPLEXITY OCEAN CLIMATE ATLANTIC CALIBRATION STRATIFICATION RECORDS SILICA |
description |
In the context of gradual Cenozoic cooling, the timing of the onset of significant Northern Hemisphere glaciation 2.7 million years ago is consistent with Milankovitch's orbital theory, which posited that ice sheets grow when polar summertime insolation and temperature are low. However, the role of moisture supply in the initiation of large Northern Hemisphere ice sheets has remained unclear. The subarctic Pacific Ocean represents a significant source of water vapour to boreal North America, but it has been largely overlooked in efforts to explain Northern Hemisphere glaciation. Here we present alkenone unsaturation ratios and diatom oxygen isotope ratios from a sediment core in the western subarctic Pacific Ocean, indicating that 2.7 million years ago late-summer sea surface temperatures in this ocean region rose in response to an increase in stratification. At the same time, winter sea surface temperatures cooled, winter floating ice became more abundant and global climate descended into glacial conditions. We suggest that the observed summer warming extended into the autumn, providing water vapour to northern North America, where it precipitated and accumulated as snow, and thus allowed the initiation of Northern Hemisphere glaciation. |
format |
Article in Journal/Newspaper |
author |
Haug, GH Ganopolski, A Sigman, DM Rosell-Mele, A Swann, GEA Tiedemann, R Jaccard, SL Bollmann, J Maslin, MA Leng, MJ Eglinton, G |
author_facet |
Haug, GH Ganopolski, A Sigman, DM Rosell-Mele, A Swann, GEA Tiedemann, R Jaccard, SL Bollmann, J Maslin, MA Leng, MJ Eglinton, G |
author_sort |
Haug, GH |
title |
North Pacific seasonality and the glaciation of North America 2.7 million years ago |
title_short |
North Pacific seasonality and the glaciation of North America 2.7 million years ago |
title_full |
North Pacific seasonality and the glaciation of North America 2.7 million years ago |
title_fullStr |
North Pacific seasonality and the glaciation of North America 2.7 million years ago |
title_full_unstemmed |
North Pacific seasonality and the glaciation of North America 2.7 million years ago |
title_sort |
north pacific seasonality and the glaciation of north america 2.7 million years ago |
publisher |
NATURE PUBLISHING GROUP |
publishDate |
2005 |
url |
http://discovery.ucl.ac.uk/182640/ |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
Arctic Subarctic |
genre_facet |
Arctic Subarctic |
op_source |
NATURE , 433 (7028) 821 - 825. (2005) |
_version_ |
1766337903538995200 |