Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography
The influence of a reduced Greenland Ice Sheet (GrIS) on Greenland's surface climate during the Eemian interglacial is studied using a set of simulations with different GrIS realizations performed with a comprehensive climate model. We find a distinct impact of changes in the GrIS topography on...
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ftdatacite:10.7892/boris.54295 2023-05-15T16:27:47+02:00 Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography Merz, Niklaus Born, Andreas Raible, Christoph Fischer, Hubertus Stocker, Thomas 2014 application/pdf https://dx.doi.org/10.7892/boris.54295 http://boris.unibe.ch/54295/ en eng Copernicus Publications info:eu-repo/semantics/openAccess 530 Physics 550 Earth sciences & geology CreativeWork article 2014 ftdatacite https://doi.org/10.7892/boris.54295 2021-11-05T12:55:41Z The influence of a reduced Greenland Ice Sheet (GrIS) on Greenland's surface climate during the Eemian interglacial is studied using a set of simulations with different GrIS realizations performed with a comprehensive climate model. We find a distinct impact of changes in the GrIS topography on Greenland's surface air temperatures (SAT) even when correcting for changes in surface elevation, which influences SAT through the lapse rate effect. The resulting lapse-rate-corrected SAT anomalies are thermodynamically driven by changes in the local surface energy balance rather than dynamically caused through anomalous advection of warm/cold air masses. The large-scale circulation is indeed very stable among all sensitivity experiments and the Northern Hemisphere (NH) flow pattern does not depend on Greenland's topography in the Eemian. In contrast, Greenland's surface energy balance is clearly influenced by changes in the GrIS topography and this impact is seasonally diverse. In winter, the variable reacting strongest to changes in the topography is the sensible heat flux (SHF). The reason is its dependence on surface winds, which themselves are controlled to a large extent by the shape of the GrIS. Hence, regions where a receding GrIS causes higher surface wind velocities also experience anomalous warming through SHF. Vice-versa, regions that become flat and ice-free are characterized by low wind speeds, low SHF, and anomalous low winter temperatures. In summer, we find surface warming induced by a decrease in surface albedo in deglaciated areas and regions which experience surface melting. The Eemian temperature records derived from Greenland proxies, thus, likely include a temperature signal arising from changes in the GrIS topography. For the Eemian ice found in the NEEM core, our model suggests that up to 3.1 °C of the annual mean Eemian warming can be attributed to these topography-related processes and hence is not necessarily linked to large-scale climate variations. Article in Journal/Newspaper Greenland Ice Sheet DataCite Metadata Store (German National Library of Science and Technology) Greenland |
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Open Polar |
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language |
English |
topic |
530 Physics 550 Earth sciences & geology |
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530 Physics 550 Earth sciences & geology Merz, Niklaus Born, Andreas Raible, Christoph Fischer, Hubertus Stocker, Thomas Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography |
topic_facet |
530 Physics 550 Earth sciences & geology |
description |
The influence of a reduced Greenland Ice Sheet (GrIS) on Greenland's surface climate during the Eemian interglacial is studied using a set of simulations with different GrIS realizations performed with a comprehensive climate model. We find a distinct impact of changes in the GrIS topography on Greenland's surface air temperatures (SAT) even when correcting for changes in surface elevation, which influences SAT through the lapse rate effect. The resulting lapse-rate-corrected SAT anomalies are thermodynamically driven by changes in the local surface energy balance rather than dynamically caused through anomalous advection of warm/cold air masses. The large-scale circulation is indeed very stable among all sensitivity experiments and the Northern Hemisphere (NH) flow pattern does not depend on Greenland's topography in the Eemian. In contrast, Greenland's surface energy balance is clearly influenced by changes in the GrIS topography and this impact is seasonally diverse. In winter, the variable reacting strongest to changes in the topography is the sensible heat flux (SHF). The reason is its dependence on surface winds, which themselves are controlled to a large extent by the shape of the GrIS. Hence, regions where a receding GrIS causes higher surface wind velocities also experience anomalous warming through SHF. Vice-versa, regions that become flat and ice-free are characterized by low wind speeds, low SHF, and anomalous low winter temperatures. In summer, we find surface warming induced by a decrease in surface albedo in deglaciated areas and regions which experience surface melting. The Eemian temperature records derived from Greenland proxies, thus, likely include a temperature signal arising from changes in the GrIS topography. For the Eemian ice found in the NEEM core, our model suggests that up to 3.1 °C of the annual mean Eemian warming can be attributed to these topography-related processes and hence is not necessarily linked to large-scale climate variations. |
format |
Article in Journal/Newspaper |
author |
Merz, Niklaus Born, Andreas Raible, Christoph Fischer, Hubertus Stocker, Thomas |
author_facet |
Merz, Niklaus Born, Andreas Raible, Christoph Fischer, Hubertus Stocker, Thomas |
author_sort |
Merz, Niklaus |
title |
Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography |
title_short |
Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography |
title_full |
Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography |
title_fullStr |
Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography |
title_full_unstemmed |
Dependence of Eemian Greenland temperature reconstructions on the ice sheet topography |
title_sort |
dependence of eemian greenland temperature reconstructions on the ice sheet topography |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://dx.doi.org/10.7892/boris.54295 http://boris.unibe.ch/54295/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.7892/boris.54295 |
_version_ |
1766017303210622976 |