Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core
Seasonal temperature reconstructions from ice cores are missing over glacial–interglacial timescales, preventing a good understanding of the driving factors of Antarctic past climate changes. Here the total air content (TAC) record from the Antarctic EPICA Dome C (EDC) ice core is analyzed over the...
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ftcopernicus:oai:publications.copernicus.org:cp115374 2024-09-15T17:42:43+00:00 Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core Raynaud, Dominique Yin, Qiuzhen Capron, Emilie Wu, Zhipeng Parrenin, Frédéric Berger, André Lipenkov, Vladimir 2024-06-11 application/pdf https://doi.org/10.5194/cp-20-1269-2024 https://cp.copernicus.org/articles/20/1269/2024/ eng eng doi:10.5194/cp-20-1269-2024 https://cp.copernicus.org/articles/20/1269/2024/ eISSN: 1814-9332 Text 2024 ftcopernicus https://doi.org/10.5194/cp-20-1269-2024 2024-08-28T05:24:22Z Seasonal temperature reconstructions from ice cores are missing over glacial–interglacial timescales, preventing a good understanding of the driving factors of Antarctic past climate changes. Here the total air content (TAC) record from the Antarctic EPICA Dome C (EDC) ice core is analyzed over the last 440 ka (thousand years). While the water isotopic record, a tracer for annual mean surface temperature, exhibits a dominant ∼100 kyr cyclicity, the TAC record is associated with a dominant ∼40 kyr cyclicity. Our results show that the TAC record is anti-correlated with the mean insolation over the local astronomical summer half-year. They also show for the first time that it is highly anti-correlated with local summer temperature simulated with an Earth system model of intermediate complexity. We propose that (1) the local summer insolation controls the local summer temperature; (2) the latter, through the development of temperature gradients at the near-surface of the ice sheet ( <2 m), is affecting the surface snow structure; and (3) those snow structure changes propagating down to the bottom of the firn through densification are eventually controlling the pore volume at the bubble close-off and consequently the TAC. Hence, our results suggest that the EDC TAC record could be used as a proxy for local summer temperature changes. Also, our new simulations show that the mean insolation over the local astronomical summer half-year is the primary driver of Antarctic summer surface temperature variations, while changes in atmospheric greenhouse gas (GHG) concentrations and Northern Hemisphere (NH) ice sheet configurations play a more important role in Antarctic annual surface temperature changes. Text Antarc* Antarctic EPICA ice core Ice Sheet Copernicus Publications: E-Journals Climate of the Past 20 6 1269 1282 |
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Copernicus Publications: E-Journals |
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English |
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Seasonal temperature reconstructions from ice cores are missing over glacial–interglacial timescales, preventing a good understanding of the driving factors of Antarctic past climate changes. Here the total air content (TAC) record from the Antarctic EPICA Dome C (EDC) ice core is analyzed over the last 440 ka (thousand years). While the water isotopic record, a tracer for annual mean surface temperature, exhibits a dominant ∼100 kyr cyclicity, the TAC record is associated with a dominant ∼40 kyr cyclicity. Our results show that the TAC record is anti-correlated with the mean insolation over the local astronomical summer half-year. They also show for the first time that it is highly anti-correlated with local summer temperature simulated with an Earth system model of intermediate complexity. We propose that (1) the local summer insolation controls the local summer temperature; (2) the latter, through the development of temperature gradients at the near-surface of the ice sheet ( <2 m), is affecting the surface snow structure; and (3) those snow structure changes propagating down to the bottom of the firn through densification are eventually controlling the pore volume at the bubble close-off and consequently the TAC. Hence, our results suggest that the EDC TAC record could be used as a proxy for local summer temperature changes. Also, our new simulations show that the mean insolation over the local astronomical summer half-year is the primary driver of Antarctic summer surface temperature variations, while changes in atmospheric greenhouse gas (GHG) concentrations and Northern Hemisphere (NH) ice sheet configurations play a more important role in Antarctic annual surface temperature changes. |
format |
Text |
author |
Raynaud, Dominique Yin, Qiuzhen Capron, Emilie Wu, Zhipeng Parrenin, Frédéric Berger, André Lipenkov, Vladimir |
spellingShingle |
Raynaud, Dominique Yin, Qiuzhen Capron, Emilie Wu, Zhipeng Parrenin, Frédéric Berger, André Lipenkov, Vladimir Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core |
author_facet |
Raynaud, Dominique Yin, Qiuzhen Capron, Emilie Wu, Zhipeng Parrenin, Frédéric Berger, André Lipenkov, Vladimir |
author_sort |
Raynaud, Dominique |
title |
Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core |
title_short |
Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core |
title_full |
Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core |
title_fullStr |
Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core |
title_full_unstemmed |
Local summer temperature changes over the past 440 ka revealed by the total air content in the Antarctic EPICA Dome C ice core |
title_sort |
local summer temperature changes over the past 440 ka revealed by the total air content in the antarctic epica dome c ice core |
publishDate |
2024 |
url |
https://doi.org/10.5194/cp-20-1269-2024 https://cp.copernicus.org/articles/20/1269/2024/ |
genre |
Antarc* Antarctic EPICA ice core Ice Sheet |
genre_facet |
Antarc* Antarctic EPICA ice core Ice Sheet |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-20-1269-2024 https://cp.copernicus.org/articles/20/1269/2024/ |
op_doi |
https://doi.org/10.5194/cp-20-1269-2024 |
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Climate of the Past |
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20 |
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6 |
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1282 |
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1810489428660977664 |