Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core
Together with the latent heat stored in glacial ice sheets, the ocean heat uptake carries the lion's share of glacial–interglacial changes in the planetary heat content, but little direct information on the global mean ocean temperature (MOT) is available to constrain the ocean temperature resp...
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ftdoajarticles:oai:doaj.org/article:b9b9f2f3ff274043a8857eae89274515 2023-05-15T14:03:23+02:00 Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core M. Haeberli D. Baggenstos J. Schmitt M. Grimmer A. Michel T. Kellerhals H. Fischer 2021-04-01T00:00:00Z https://doi.org/10.5194/cp-17-843-2021 https://doaj.org/article/b9b9f2f3ff274043a8857eae89274515 EN eng Copernicus Publications https://cp.copernicus.org/articles/17/843/2021/cp-17-843-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-843-2021 1814-9324 1814-9332 https://doaj.org/article/b9b9f2f3ff274043a8857eae89274515 Climate of the Past, Vol 17, Pp 843-867 (2021) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/cp-17-843-2021 2022-12-31T15:51:07Z Together with the latent heat stored in glacial ice sheets, the ocean heat uptake carries the lion's share of glacial–interglacial changes in the planetary heat content, but little direct information on the global mean ocean temperature (MOT) is available to constrain the ocean temperature response to glacial–interglacial climate perturbations. Using ratios of noble gases and molecular nitrogen trapped in the Antarctic EPICA Dome C ice core, we are able to reconstruct MOT for peak glacial and interglacial conditions during the last 700 000 years and explore the differences between these extrema. To this end, we have to correct the noble gas ratios for gas transport effects in the firn column and gas loss fractionation processes of the samples after ice core retrieval using the full elemental matrix of N 2 , Ar, Kr, and Xe in the ice and their individual isotopic ratios. The reconstructed MOT in peak glacials is consistently about 3.3 ± 0.4 ∘ C cooler compared to the Holocene. Lukewarm interglacials before the Mid-Brunhes Event 450 kyr ago are characterized by 1.6 ± 0.4 ∘ C lower MOT than the Holocene; thus, glacial–interglacial amplitudes were only about 50 % of those after the Mid-Brunhes Event, in line with the reduced radiative forcing by lower greenhouse gas concentrations and their Earth system feedbacks. Moreover, we find significantly increased MOTs at the onset of Marine Isotope Stage 5.5 and 9.3, which are coeval with CO 2 and CH 4 overshoots at that time. We link these CO 2 and CH 4 overshoots to a resumption of the Atlantic Meridional Overturning Circulation, which is also the starting point of the release of heat previously accumulated in the ocean during times of reduced overturning. Article in Journal/Newspaper Antarc* Antarctic EPICA ice core Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Climate of the Past 17 2 843 867 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 M. Haeberli D. Baggenstos J. Schmitt M. Grimmer A. Michel T. Kellerhals H. Fischer Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Together with the latent heat stored in glacial ice sheets, the ocean heat uptake carries the lion's share of glacial–interglacial changes in the planetary heat content, but little direct information on the global mean ocean temperature (MOT) is available to constrain the ocean temperature response to glacial–interglacial climate perturbations. Using ratios of noble gases and molecular nitrogen trapped in the Antarctic EPICA Dome C ice core, we are able to reconstruct MOT for peak glacial and interglacial conditions during the last 700 000 years and explore the differences between these extrema. To this end, we have to correct the noble gas ratios for gas transport effects in the firn column and gas loss fractionation processes of the samples after ice core retrieval using the full elemental matrix of N 2 , Ar, Kr, and Xe in the ice and their individual isotopic ratios. The reconstructed MOT in peak glacials is consistently about 3.3 ± 0.4 ∘ C cooler compared to the Holocene. Lukewarm interglacials before the Mid-Brunhes Event 450 kyr ago are characterized by 1.6 ± 0.4 ∘ C lower MOT than the Holocene; thus, glacial–interglacial amplitudes were only about 50 % of those after the Mid-Brunhes Event, in line with the reduced radiative forcing by lower greenhouse gas concentrations and their Earth system feedbacks. Moreover, we find significantly increased MOTs at the onset of Marine Isotope Stage 5.5 and 9.3, which are coeval with CO 2 and CH 4 overshoots at that time. We link these CO 2 and CH 4 overshoots to a resumption of the Atlantic Meridional Overturning Circulation, which is also the starting point of the release of heat previously accumulated in the ocean during times of reduced overturning. |
format |
Article in Journal/Newspaper |
author |
M. Haeberli D. Baggenstos J. Schmitt M. Grimmer A. Michel T. Kellerhals H. Fischer |
author_facet |
M. Haeberli D. Baggenstos J. Schmitt M. Grimmer A. Michel T. Kellerhals H. Fischer |
author_sort |
M. Haeberli |
title |
Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core |
title_short |
Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core |
title_full |
Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core |
title_fullStr |
Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core |
title_full_unstemmed |
Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core |
title_sort |
snapshots of mean ocean temperature over the last 700 000 years using noble gases in the epica dome c ice core |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-843-2021 https://doaj.org/article/b9b9f2f3ff274043a8857eae89274515 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic EPICA ice core |
genre_facet |
Antarc* Antarctic EPICA ice core |
op_source |
Climate of the Past, Vol 17, Pp 843-867 (2021) |
op_relation |
https://cp.copernicus.org/articles/17/843/2021/cp-17-843-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-843-2021 1814-9324 1814-9332 https://doaj.org/article/b9b9f2f3ff274043a8857eae89274515 |
op_doi |
https://doi.org/10.5194/cp-17-843-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
2 |
container_start_page |
843 |
op_container_end_page |
867 |
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1766274026573922304 |