Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials
Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than preindustrial (CO2~280 ppm) in each of the last four interglacials. During the previous three interglacials...
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ftunivreading:oai:centaur.reading.ac.uk:33548 2024-06-23T07:45:49+00:00 Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials Holden, P. B. Edwards, N. R. Wolff, E. W. Lang, N. J. Singarayer, J. S. Valdes, P. J. Stocker, T. F. 2010 text https://centaur.reading.ac.uk/33548/ https://centaur.reading.ac.uk/33548/1/cp-6-431-2010.pdf en eng Copernicus on behalf of the European Geosciences Union https://centaur.reading.ac.uk/33548/1/cp-6-431-2010.pdf Holden, P. B., Edwards, N. R., Wolff, E. W., Lang, N. J., Singarayer, J. S. <https://centaur.reading.ac.uk/view/creators/90005422.html>, Valdes, P. J. and Stocker, T. F. (2010) Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials. Climate of the Past, 6 (4). pp. 431-443. ISSN 1814-9332 doi: https://doi.org/10.5194/cp-6-431-2010 <https://doi.org/10.5194/cp-6-431-2010> cc_by Article PeerReviewed 2010 ftunivreading https://doi.org/10.5194/cp-6-431-2010 2024-06-11T15:01:09Z Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than preindustrial (CO2~280 ppm) in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (~3000 years) and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as "Warmer than Present Transients" (WPTs). We present a series of experiments to investigate the impact of deglacial meltwater on the Atlantic Meridional Overturning Circulation (AMOC) and Antarctic temperature. It is well known that a slowed AMOC would increase southern sea surface temperature (SST) through the bipolar seesaw and observational data suggests that the AMOC remained weak throughout the terminations preceding WPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. We present two 800 kyr transient simulations using the Intermediate Complexity model GENIE-1 which demonstrate that meltwater forcing generates transient southern warming that is consistent with the timing of WPTs, but is not sufficient (in this single parameterisation) to reproduce the magnitude of observed warmth. In order to investigate model and boundary condition uncertainty, we present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP) and three snapshot HadCM3 simulations at 130 000 BP. Only with consideration of the possible feedback of West Antarctic Ice Sheet (WAIS) retreat does it become possible to simulate the magnitude of observed warming. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica ice core Ice Sheet CentAUR: Central Archive at the University of Reading Antarctic East Antarctica West Antarctic Ice Sheet Climate of the Past 6 4 431 443 |
institution |
Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than preindustrial (CO2~280 ppm) in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (~3000 years) and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as "Warmer than Present Transients" (WPTs). We present a series of experiments to investigate the impact of deglacial meltwater on the Atlantic Meridional Overturning Circulation (AMOC) and Antarctic temperature. It is well known that a slowed AMOC would increase southern sea surface temperature (SST) through the bipolar seesaw and observational data suggests that the AMOC remained weak throughout the terminations preceding WPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. We present two 800 kyr transient simulations using the Intermediate Complexity model GENIE-1 which demonstrate that meltwater forcing generates transient southern warming that is consistent with the timing of WPTs, but is not sufficient (in this single parameterisation) to reproduce the magnitude of observed warmth. In order to investigate model and boundary condition uncertainty, we present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP) and three snapshot HadCM3 simulations at 130 000 BP. Only with consideration of the possible feedback of West Antarctic Ice Sheet (WAIS) retreat does it become possible to simulate the magnitude of observed warming. |
format |
Article in Journal/Newspaper |
author |
Holden, P. B. Edwards, N. R. Wolff, E. W. Lang, N. J. Singarayer, J. S. Valdes, P. J. Stocker, T. F. |
spellingShingle |
Holden, P. B. Edwards, N. R. Wolff, E. W. Lang, N. J. Singarayer, J. S. Valdes, P. J. Stocker, T. F. Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials |
author_facet |
Holden, P. B. Edwards, N. R. Wolff, E. W. Lang, N. J. Singarayer, J. S. Valdes, P. J. Stocker, T. F. |
author_sort |
Holden, P. B. |
title |
Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials |
title_short |
Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials |
title_full |
Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials |
title_fullStr |
Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials |
title_full_unstemmed |
Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials |
title_sort |
interhemispheric coupling, the west antarctic ice sheet and warm antarctic interglacials |
publisher |
Copernicus on behalf of the European Geosciences Union |
publishDate |
2010 |
url |
https://centaur.reading.ac.uk/33548/ https://centaur.reading.ac.uk/33548/1/cp-6-431-2010.pdf |
geographic |
Antarctic East Antarctica West Antarctic Ice Sheet |
geographic_facet |
Antarctic East Antarctica West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica East Antarctica ice core Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica ice core Ice Sheet |
op_relation |
https://centaur.reading.ac.uk/33548/1/cp-6-431-2010.pdf Holden, P. B., Edwards, N. R., Wolff, E. W., Lang, N. J., Singarayer, J. S. <https://centaur.reading.ac.uk/view/creators/90005422.html>, Valdes, P. J. and Stocker, T. F. (2010) Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials. Climate of the Past, 6 (4). pp. 431-443. ISSN 1814-9332 doi: https://doi.org/10.5194/cp-6-431-2010 <https://doi.org/10.5194/cp-6-431-2010> |
op_rights |
cc_by |
op_doi |
https://doi.org/10.5194/cp-6-431-2010 |
container_title |
Climate of the Past |
container_volume |
6 |
container_issue |
4 |
container_start_page |
431 |
op_container_end_page |
443 |
_version_ |
1802642476550324224 |