Unstable AMOC during glacial intervals and millennial variability: The role of mean sea ice extent
Abstract
A striking feature of paleoclimate records is the greater stability of the Holocene epoch relative to the preceding glacial interval, especially apparent in the North Atlantic region. In particular, strong irregular variability with an approximately 1500 yr period, known as the Dansgaard-Oeschger (D-O) events, punctuates the last glaciation, but is absent during the interglacial. Prevailing theories, modeling and data suggest that these events, seen as abrupt warming episodes in Greenland ice cores and sea surface temperature records in the North Atlantic, are linked to reorganizations of the Atlantic Meridional Overturning Circulation (AMOC). In this study, using a new low-order ocean model that reproduces a realistic power spectrum of millennial variability, we explore differences in the AMOC stability between glacial and interglacial intervals of the 100 kyr glacial cycle of the Late Pleistocene (1 kyr = 1000 yr). Previous modeling studies show that the edge of sea ice in the North Atlantic shifts southward during glacial intervals, moving the region of the North Atlantic Deep Water formation and the AMOC also southward. Finally, here we demonstrate that, by shifting the AMOC with respect to the mean atmospheric precipitation field, such a displacement makes the system unstable, which explains chaotic millennial variabilitymore »
- Authors:
- Publication Date:
- Research Org.:
- Univ. of Southampton (United Kingdom). Ocean and Earth Science, National Oceanography Centre Southampton
- Sponsoring Org.:
- USDOE Office of Science (SC); National Science Foundation (NSF)
- OSTI Identifier:
- 1210105
- Alternate Identifier(s):
- OSTI ID: 1437176
- Grant/Contract Number:
- SC0007037; AGS-1405272
- Resource Type:
- Published Article
- Journal Name:
- Earth and Planetary Science Letters
- Additional Journal Information:
- Journal Name: Earth and Planetary Science Letters Journal Volume: 429 Journal Issue: C; Journal ID: ISSN 0012-821X
- Publisher:
- Elsevier
- Country of Publication:
- Netherlands
- Language:
- English
- Subject:
- 58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES; Atlantic meridional overturning circulation; Holocene climate stability; Dansgaard–Oeschger events; millennial climate variability; glacial–interglacial cycle
Citation Formats
Sévellec, Florian, and Fedorov, Alexey V. Unstable AMOC during glacial intervals and millennial variability: The role of mean sea ice extent. Netherlands: N. p., 2015.
Web. doi:10.1016/j.epsl.2015.07.022.
Sévellec, Florian, & Fedorov, Alexey V. Unstable AMOC during glacial intervals and millennial variability: The role of mean sea ice extent. Netherlands. https://doi.org/10.1016/j.epsl.2015.07.022
Sévellec, Florian, and Fedorov, Alexey V. Sun .
"Unstable AMOC during glacial intervals and millennial variability: The role of mean sea ice extent". Netherlands. https://doi.org/10.1016/j.epsl.2015.07.022.
@article{osti_1210105,
title = {Unstable AMOC during glacial intervals and millennial variability: The role of mean sea ice extent},
author = {Sévellec, Florian and Fedorov, Alexey V.},
abstractNote = {A striking feature of paleoclimate records is the greater stability of the Holocene epoch relative to the preceding glacial interval, especially apparent in the North Atlantic region. In particular, strong irregular variability with an approximately 1500 yr period, known as the Dansgaard-Oeschger (D-O) events, punctuates the last glaciation, but is absent during the interglacial. Prevailing theories, modeling and data suggest that these events, seen as abrupt warming episodes in Greenland ice cores and sea surface temperature records in the North Atlantic, are linked to reorganizations of the Atlantic Meridional Overturning Circulation (AMOC). In this study, using a new low-order ocean model that reproduces a realistic power spectrum of millennial variability, we explore differences in the AMOC stability between glacial and interglacial intervals of the 100 kyr glacial cycle of the Late Pleistocene (1 kyr = 1000 yr). Previous modeling studies show that the edge of sea ice in the North Atlantic shifts southward during glacial intervals, moving the region of the North Atlantic Deep Water formation and the AMOC also southward. Finally, here we demonstrate that, by shifting the AMOC with respect to the mean atmospheric precipitation field, such a displacement makes the system unstable, which explains chaotic millennial variability during the glacials and the persistence of stable ocean conditions during the interglacials.},
doi = {10.1016/j.epsl.2015.07.022},
journal = {Earth and Planetary Science Letters},
number = C,
volume = 429,
place = {Netherlands},
year = {Sun Nov 01 00:00:00 EDT 2015},
month = {Sun Nov 01 00:00:00 EDT 2015}
}
https://doi.org/10.1016/j.epsl.2015.07.022
Web of Science