The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period
The Last Glacial Maximum (LGM; 21 000 yr before present) was a period of low atmospheric greenhouse gas concentrations, when vast ice sheets covered large parts of North America and Europe. Paleoclimate reconstructions and modeling studies suggest that the atmospheric circulation was substantially a...
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ftunivbergen:oai:bora.uib.no:1956/9431 2023-05-15T16:40:06+02:00 The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period Pausata, Francesco S. R. Li, Camille Wettstein, Justin Kageyama, M. Nisancioglu, Kerim Hestnes 2011-10-18 application/pdf https://hdl.handle.net/1956/9431 https://doi.org/10.5194/cp-7-1089-2011 eng eng Copernicus Publications European Geosciences Union Past climate variability: model analysis and proxy intercomparison urn:issn:1814-9324 https://hdl.handle.net/1956/9431 https://doi.org/10.5194/cp-7-1089-2011 cristin:835797 Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright Author(s) 2011. Climate of the Past 7 1089-1101 Peer reviewed Journal article 2011 ftunivbergen https://doi.org/10.5194/cp-7-1089-2011 2023-03-14T17:44:38Z The Last Glacial Maximum (LGM; 21 000 yr before present) was a period of low atmospheric greenhouse gas concentrations, when vast ice sheets covered large parts of North America and Europe. Paleoclimate reconstructions and modeling studies suggest that the atmospheric circulation was substantially altered compared to today, both in terms of its mean state and its variability. Here we present a suite of coupled model simulations designed to investigate both the separate and combined influences of the main LGM boundary condition changes (greenhouse gases, ice sheet topography and ice sheet albedo) on the mean state and variability of the atmospheric circulation as represented by sea level pressure (SLP) and 200-hPa zonal wind in the North Atlantic sector. We find that ice sheet topography accounts for most of the simulated changes during the LGM. Greenhouse gases and ice sheet albedo affect the SLP gradient in the North Atlantic, but the overall placement of high and low pressure centers is controlled by topography. Additional analysis shows that North Atlantic sea surface temperatures and sea ice edge position do not substantially influence the pattern of the climatological-mean SLP field, SLP variability or the position of the North Atlantic jet in the LGM. publishedVersion Article in Journal/Newspaper Ice Sheet North Atlantic Sea ice University of Bergen: Bergen Open Research Archive (BORA-UiB) Climate of the Past 7 4 1089 1101 |
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Open Polar |
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University of Bergen: Bergen Open Research Archive (BORA-UiB) |
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ftunivbergen |
language |
English |
description |
The Last Glacial Maximum (LGM; 21 000 yr before present) was a period of low atmospheric greenhouse gas concentrations, when vast ice sheets covered large parts of North America and Europe. Paleoclimate reconstructions and modeling studies suggest that the atmospheric circulation was substantially altered compared to today, both in terms of its mean state and its variability. Here we present a suite of coupled model simulations designed to investigate both the separate and combined influences of the main LGM boundary condition changes (greenhouse gases, ice sheet topography and ice sheet albedo) on the mean state and variability of the atmospheric circulation as represented by sea level pressure (SLP) and 200-hPa zonal wind in the North Atlantic sector. We find that ice sheet topography accounts for most of the simulated changes during the LGM. Greenhouse gases and ice sheet albedo affect the SLP gradient in the North Atlantic, but the overall placement of high and low pressure centers is controlled by topography. Additional analysis shows that North Atlantic sea surface temperatures and sea ice edge position do not substantially influence the pattern of the climatological-mean SLP field, SLP variability or the position of the North Atlantic jet in the LGM. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Pausata, Francesco S. R. Li, Camille Wettstein, Justin Kageyama, M. Nisancioglu, Kerim Hestnes |
spellingShingle |
Pausata, Francesco S. R. Li, Camille Wettstein, Justin Kageyama, M. Nisancioglu, Kerim Hestnes The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period |
author_facet |
Pausata, Francesco S. R. Li, Camille Wettstein, Justin Kageyama, M. Nisancioglu, Kerim Hestnes |
author_sort |
Pausata, Francesco S. R. |
title |
The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period |
title_short |
The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period |
title_full |
The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period |
title_fullStr |
The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period |
title_full_unstemmed |
The key role of topography in altering North Atlantic atmospheric circulation during the last glacial period |
title_sort |
key role of topography in altering north atlantic atmospheric circulation during the last glacial period |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://hdl.handle.net/1956/9431 https://doi.org/10.5194/cp-7-1089-2011 |
genre |
Ice Sheet North Atlantic Sea ice |
genre_facet |
Ice Sheet North Atlantic Sea ice |
op_source |
Climate of the Past 7 1089-1101 |
op_relation |
Past climate variability: model analysis and proxy intercomparison urn:issn:1814-9324 https://hdl.handle.net/1956/9431 https://doi.org/10.5194/cp-7-1089-2011 cristin:835797 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/3.0/ Copyright Author(s) 2011. |
op_doi |
https://doi.org/10.5194/cp-7-1089-2011 |
container_title |
Climate of the Past |
container_volume |
7 |
container_issue |
4 |
container_start_page |
1089 |
op_container_end_page |
1101 |
_version_ |
1766030474265755648 |