Migration of the Antarctic Polar Front over the last glacial cycle
The Southern Hemisphere Westerly Winds (SWW) drive upwelling south of the Antarctic Polar Front (PF) that vents CO2 to the atmosphere. During the ice ages, a northward (equatorward) shift of the PF may have reduced this CO2 venting, helping to explain the lower atmospheric CO2 concentration of those...
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ftpubman:oai:pure.mpg.de:item_3473308 2023-08-27T04:05:53+02:00 Migration of the Antarctic Polar Front over the last glacial cycle Thöle, L. Ai, X. Auderset, A. Schmitt, M. Moretti, S. Studer, A. Michel, E. Wegmann, M. Mazaud, A. Bijl, P. Sigman, D. Martinez-Garcia, A. Jaccard, S. 2022-03-08 http://hdl.handle.net/21.11116/0000-000B-68D9-C eng eng info:eu-repo/semantics/altIdentifier/doi/10.21203/rs.3.rs-1364006/v1 http://hdl.handle.net/21.11116/0000-000B-68D9-C info:eu-repo/semantics/preprint 2022 ftpubman https://doi.org/10.21203/rs.3.rs-1364006/v1 2023-08-02T01:21:38Z The Southern Hemisphere Westerly Winds (SWW) drive upwelling south of the Antarctic Polar Front (PF) that vents CO2 to the atmosphere. During the ice ages, a northward (equatorward) shift of the PF may have reduced this CO2 venting, helping to explain the lower atmospheric CO2 concentration of those times. However, evidence of PF migration is lacking. Here, we report biomarker–based sea surface temperature (SST) reconstructions from two marine sediment cores at different latitudes in the Southern Indian Ocean across the last glacial cycle. Using a quantitative framework for the effect of the PF on meridional SST gradient, we show that the PF underwent an equatorward shift during the ice ages. The PF latitude reconstruction, when compared with other data, also suggests a role for Earth’s axial tilt in the strength and latitude range of SWW-driven upwelling, which may explain previously noted deviations in atmospheric CO2 from a simple correlation with Antarctic climate. Report Antarc* Antarctic Max Planck Society: MPG.PuRe Antarctic Indian The Antarctic |
institution |
Open Polar |
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Max Planck Society: MPG.PuRe |
op_collection_id |
ftpubman |
language |
English |
description |
The Southern Hemisphere Westerly Winds (SWW) drive upwelling south of the Antarctic Polar Front (PF) that vents CO2 to the atmosphere. During the ice ages, a northward (equatorward) shift of the PF may have reduced this CO2 venting, helping to explain the lower atmospheric CO2 concentration of those times. However, evidence of PF migration is lacking. Here, we report biomarker–based sea surface temperature (SST) reconstructions from two marine sediment cores at different latitudes in the Southern Indian Ocean across the last glacial cycle. Using a quantitative framework for the effect of the PF on meridional SST gradient, we show that the PF underwent an equatorward shift during the ice ages. The PF latitude reconstruction, when compared with other data, also suggests a role for Earth’s axial tilt in the strength and latitude range of SWW-driven upwelling, which may explain previously noted deviations in atmospheric CO2 from a simple correlation with Antarctic climate. |
format |
Report |
author |
Thöle, L. Ai, X. Auderset, A. Schmitt, M. Moretti, S. Studer, A. Michel, E. Wegmann, M. Mazaud, A. Bijl, P. Sigman, D. Martinez-Garcia, A. Jaccard, S. |
spellingShingle |
Thöle, L. Ai, X. Auderset, A. Schmitt, M. Moretti, S. Studer, A. Michel, E. Wegmann, M. Mazaud, A. Bijl, P. Sigman, D. Martinez-Garcia, A. Jaccard, S. Migration of the Antarctic Polar Front over the last glacial cycle |
author_facet |
Thöle, L. Ai, X. Auderset, A. Schmitt, M. Moretti, S. Studer, A. Michel, E. Wegmann, M. Mazaud, A. Bijl, P. Sigman, D. Martinez-Garcia, A. Jaccard, S. |
author_sort |
Thöle, L. |
title |
Migration of the Antarctic Polar Front over the last glacial cycle |
title_short |
Migration of the Antarctic Polar Front over the last glacial cycle |
title_full |
Migration of the Antarctic Polar Front over the last glacial cycle |
title_fullStr |
Migration of the Antarctic Polar Front over the last glacial cycle |
title_full_unstemmed |
Migration of the Antarctic Polar Front over the last glacial cycle |
title_sort |
migration of the antarctic polar front over the last glacial cycle |
publishDate |
2022 |
url |
http://hdl.handle.net/21.11116/0000-000B-68D9-C |
geographic |
Antarctic Indian The Antarctic |
geographic_facet |
Antarctic Indian The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.21203/rs.3.rs-1364006/v1 http://hdl.handle.net/21.11116/0000-000B-68D9-C |
op_doi |
https://doi.org/10.21203/rs.3.rs-1364006/v1 |
_version_ |
1775346615349936128 |