Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle
The evolution of the Antarctic Ice Sheet during the last climate cycle and the interrelation to global atmospheric and ocean circulation remains controversial and plays an important role for our understanding of ice sheet response to modern global warming. The timing and sequence of deglacial warmin...
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AGU, abstract #PP43B-1345
2017
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Online Access: | https://epic.awi.de/id/eprint/46208/ https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/225811 https://hdl.handle.net/10013/epic.0fbe2eee-aa0e-4214-bec5-b5574790f0b4 |
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institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The evolution of the Antarctic Ice Sheet during the last climate cycle and the interrelation to global atmospheric and ocean circulation remains controversial and plays an important role for our understanding of ice sheet response to modern global warming. The timing and sequence of deglacial warming is relevant for understanding the variability and sensitivity of the Antarctic Ice Sheet to climatic changes, and the continuing rise of atmospheric greenhouse gas concentrations. The Antarctic Ice Sheet is a pivotal component of the global water budget. Freshwater fluxes from the ice sheet may affect the Antarctic Circumpolar Current (ACC), which is strongly impacted by the westerly wind belt in the Southern Hemisphere (SHWW) and constricted to its narrowest extent in the Drake Passage. The flow of ACC water masses through Drake Passage is, therefore, crucial for advancing our understanding of the Southern Ocean’s role in global meridional overturning circulation and global climate change. In order to address orbital and millennial-scale variability of the Antarctic ice sheet and the ACC, we applied a multi-proxy approach on a sediment core from the central Drake Passage including grain size, iceberg-rafted debris, mineral dust, bulk chemical and mineralogical composition, and physical properties. In combination with already published and new sediment records from the Drake Passage and Scotia Sea, as well as high-resolution data from Antarctic ice cores (WDC, EDML), we now have evidence that during glacial times a more northerly extent of the perennial sea-ice zone decreased ACC current velocities in the central Drake Passage. During deglaciation the SHWW shifted southwards due to a decreasing temperature gradient between subtropical and polar latitudes caused by sea ice and ice sheet decline. This in turn caused Southern Hemisphere warming, a more vigorous ACC, stronger Southern Ocean ventilation, and warm Circumpolar Deep Water (CDW) upwelling on Antarctic shelves resulting in increased ice shelf melting. Stronger upwelling is associated with a rise in atmospheric carbon dioxide to reach a threshold at which full deglaciation could become inevitable. |
format |
Conference Object |
author |
Kuhn, Gerhard Wu, Shuzhuang Hass, Christian Klages, Johann Philipp Zheng, Xufeng Arz, Helge Esper, Oliver Hillenbrand, Claus-Dieter Lange, Carina B. Lamy, Frank Lohmann, Gerrit Müller, Juliane McCave, I. N. Nürnberg, Dirk Roberts, Jenny Tiedemann, Ralf Timmermann, A. Titschack, Jürgen Zhang, Xu |
spellingShingle |
Kuhn, Gerhard Wu, Shuzhuang Hass, Christian Klages, Johann Philipp Zheng, Xufeng Arz, Helge Esper, Oliver Hillenbrand, Claus-Dieter Lange, Carina B. Lamy, Frank Lohmann, Gerrit Müller, Juliane McCave, I. N. Nürnberg, Dirk Roberts, Jenny Tiedemann, Ralf Timmermann, A. Titschack, Jürgen Zhang, Xu Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle |
author_facet |
Kuhn, Gerhard Wu, Shuzhuang Hass, Christian Klages, Johann Philipp Zheng, Xufeng Arz, Helge Esper, Oliver Hillenbrand, Claus-Dieter Lange, Carina B. Lamy, Frank Lohmann, Gerrit Müller, Juliane McCave, I. N. Nürnberg, Dirk Roberts, Jenny Tiedemann, Ralf Timmermann, A. Titschack, Jürgen Zhang, Xu |
author_sort |
Kuhn, Gerhard |
title |
Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle |
title_short |
Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle |
title_full |
Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle |
title_fullStr |
Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle |
title_full_unstemmed |
Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle |
title_sort |
antarctic circumpolar current dynamics and their relation to antarctic ice sheet and perennial sea-ice variability in the central drake passage during the last climate cycle |
publisher |
AGU, abstract #PP43B-1345 |
publishDate |
2017 |
url |
https://epic.awi.de/id/eprint/46208/ https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/225811 https://hdl.handle.net/10013/epic.0fbe2eee-aa0e-4214-bec5-b5574790f0b4 |
geographic |
Antarctic Southern Ocean The Antarctic Drake Passage Scotia Sea |
geographic_facet |
Antarctic Southern Ocean The Antarctic Drake Passage Scotia Sea |
genre |
Antarc* Antarctic Drake Passage Ice Sheet Ice Shelf Iceberg* Scotia Sea Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Ice Sheet Ice Shelf Iceberg* Scotia Sea Sea ice Southern Ocean |
op_source |
EPIC3American Geophysical Union, Fall Meeting 2017, New Orleans, 2017-12-11-2017-12-15AGU, abstract #PP43B-1345 |
op_relation |
Kuhn, G. orcid:0000-0001-6069-7485 , Wu, S. , Hass, C. orcid:0000-0003-2649-6828 , Klages, J. P. orcid:0000-0003-0968-1183 , Zheng, X. , Arz, H. , Esper, O. orcid:0000-0002-4342-3471 , Hillenbrand, C. D. , Lange, C. B. , Lamy, F. orcid:0000-0001-5952-1765 , Lohmann, G. orcid:0000-0003-2089-733X , Müller, J. orcid:0000-0003-0724-4131 , McCave, I. N. , Nürnberg, D. , Roberts, J. orcid:0000-0002-1098-0829 , Tiedemann, R. orcid:0000-0001-7211-8049 , Timmermann, A. , Titschack, J. and Zhang, X. orcid:0000-0003-1833-9689 (2017) Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle , American Geophysical Union, Fall Meeting 2017, New Orleans, 11 December 2017 - 15 December 2017 . hdl:10013/epic.0fbe2eee-aa0e-4214-bec5-b5574790f0b4 |
_version_ |
1766221088334807040 |
spelling |
ftawi:oai:epic.awi.de:46208 2023-05-15T13:45:21+02:00 Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle Kuhn, Gerhard Wu, Shuzhuang Hass, Christian Klages, Johann Philipp Zheng, Xufeng Arz, Helge Esper, Oliver Hillenbrand, Claus-Dieter Lange, Carina B. Lamy, Frank Lohmann, Gerrit Müller, Juliane McCave, I. N. Nürnberg, Dirk Roberts, Jenny Tiedemann, Ralf Timmermann, A. Titschack, Jürgen Zhang, Xu 2017-12 https://epic.awi.de/id/eprint/46208/ https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/225811 https://hdl.handle.net/10013/epic.0fbe2eee-aa0e-4214-bec5-b5574790f0b4 unknown AGU, abstract #PP43B-1345 Kuhn, G. orcid:0000-0001-6069-7485 , Wu, S. , Hass, C. orcid:0000-0003-2649-6828 , Klages, J. P. orcid:0000-0003-0968-1183 , Zheng, X. , Arz, H. , Esper, O. orcid:0000-0002-4342-3471 , Hillenbrand, C. D. , Lange, C. B. , Lamy, F. orcid:0000-0001-5952-1765 , Lohmann, G. orcid:0000-0003-2089-733X , Müller, J. orcid:0000-0003-0724-4131 , McCave, I. N. , Nürnberg, D. , Roberts, J. orcid:0000-0002-1098-0829 , Tiedemann, R. orcid:0000-0001-7211-8049 , Timmermann, A. , Titschack, J. and Zhang, X. orcid:0000-0003-1833-9689 (2017) Antarctic Circumpolar Current Dynamics and Their Relation to Antarctic Ice Sheet and Perennial Sea-Ice Variability in the Central Drake Passage During the Last Climate Cycle , American Geophysical Union, Fall Meeting 2017, New Orleans, 11 December 2017 - 15 December 2017 . hdl:10013/epic.0fbe2eee-aa0e-4214-bec5-b5574790f0b4 EPIC3American Geophysical Union, Fall Meeting 2017, New Orleans, 2017-12-11-2017-12-15AGU, abstract #PP43B-1345 Conference notRev 2017 ftawi 2021-12-24T15:43:34Z The evolution of the Antarctic Ice Sheet during the last climate cycle and the interrelation to global atmospheric and ocean circulation remains controversial and plays an important role for our understanding of ice sheet response to modern global warming. The timing and sequence of deglacial warming is relevant for understanding the variability and sensitivity of the Antarctic Ice Sheet to climatic changes, and the continuing rise of atmospheric greenhouse gas concentrations. The Antarctic Ice Sheet is a pivotal component of the global water budget. Freshwater fluxes from the ice sheet may affect the Antarctic Circumpolar Current (ACC), which is strongly impacted by the westerly wind belt in the Southern Hemisphere (SHWW) and constricted to its narrowest extent in the Drake Passage. The flow of ACC water masses through Drake Passage is, therefore, crucial for advancing our understanding of the Southern Ocean’s role in global meridional overturning circulation and global climate change. In order to address orbital and millennial-scale variability of the Antarctic ice sheet and the ACC, we applied a multi-proxy approach on a sediment core from the central Drake Passage including grain size, iceberg-rafted debris, mineral dust, bulk chemical and mineralogical composition, and physical properties. In combination with already published and new sediment records from the Drake Passage and Scotia Sea, as well as high-resolution data from Antarctic ice cores (WDC, EDML), we now have evidence that during glacial times a more northerly extent of the perennial sea-ice zone decreased ACC current velocities in the central Drake Passage. During deglaciation the SHWW shifted southwards due to a decreasing temperature gradient between subtropical and polar latitudes caused by sea ice and ice sheet decline. This in turn caused Southern Hemisphere warming, a more vigorous ACC, stronger Southern Ocean ventilation, and warm Circumpolar Deep Water (CDW) upwelling on Antarctic shelves resulting in increased ice shelf melting. Stronger upwelling is associated with a rise in atmospheric carbon dioxide to reach a threshold at which full deglaciation could become inevitable. Conference Object Antarc* Antarctic Drake Passage Ice Sheet Ice Shelf Iceberg* Scotia Sea Sea ice Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Southern Ocean The Antarctic Drake Passage Scotia Sea |