Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments
The Antarctic temperature changes over the past millennia remain more uncertain than in many other continental regions. This has several origins: (1) the number of high-resolution ice cores is small, in particular on the East Antarctic plateau and in some coastal areas in East Antarctica; (2) the sh...
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Online Access: | https://doi.org/10.5194/cp-15-661-2019 https://cp.copernicus.org/articles/15/661/2019/ |
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fttriple:oai:gotriple.eu:16u-WSxlJza4Xm0gPfp-y 2023-05-15T13:50:25+02:00 Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments Klein, François Abram, Nerilie J. Curran, Mark A. J. Goosse, Hugues Goursaud, Sentia Masson-Delmotte, Valérie Moy, Andrew Neukom, Raphael Orsi, Anaïs Sjolte, Jesper Steiger, Nathan Stenni, Barbara Werner, Martin 2019-04-05 https://doi.org/10.5194/cp-15-661-2019 https://cp.copernicus.org/articles/15/661/2019/ en eng Copernicus Publications doi:10.5194/cp-15-661-2019 10670/1.zyuovd 1814-9324 1814-9332 https://cp.copernicus.org/articles/15/661/2019/ undefined Geographica Helvetica - geography eISSN: 1814-9332 geo envir Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2019 fttriple https://doi.org/10.5194/cp-15-661-2019 2023-01-22T17:39:34Z The Antarctic temperature changes over the past millennia remain more uncertain than in many other continental regions. This has several origins: (1) the number of high-resolution ice cores is small, in particular on the East Antarctic plateau and in some coastal areas in East Antarctica; (2) the short and spatially sparse instrumental records limit the calibration period for reconstructions and the assessment of the methodologies; (3) the link between isotope records from ice cores and local climate is usually complex and dependent on the spatial scales and timescales investigated. Here, we use climate model results, pseudoproxy experiments and data assimilation experiments to assess the potential for reconstructing the Antarctic temperature over the last 2 millennia based on a new database of stable oxygen isotopes in ice cores compiled in the framework of Antarctica2k (Stenni et al., 2017). The well-known covariance between δ18O and temperature is reproduced in the two isotope-enabled models used (ECHAM5/MPI-OM and ECHAM5-wiso), but is generally weak over the different Antarctic regions, limiting the skill of the reconstructions. Furthermore, the strength of the link displays large variations over the past millennium, further affecting the potential skill of temperature reconstructions based on statistical methods which rely on the assumption that the last decades are a good estimate for longer temperature reconstructions. Using a data assimilation technique allows, in theory, for changes in the δ18O–temperature link through time and space to be taken into account. Pseudoproxy experiments confirm the benefits of using data assimilation methods instead of statistical methods that provide reconstructions with unrealistic variances in some Antarctic subregions. They also confirm that the relatively weak link between both variables leads to a limited potential for reconstructing temperature based on δ18O. However, the reconstruction skill is higher and more uniform among reconstruction methods when the ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Unknown Antarctic East Antarctica The Antarctic Climate of the Past 15 2 661 684 |
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spellingShingle |
geo envir Klein, François Abram, Nerilie J. Curran, Mark A. J. Goosse, Hugues Goursaud, Sentia Masson-Delmotte, Valérie Moy, Andrew Neukom, Raphael Orsi, Anaïs Sjolte, Jesper Steiger, Nathan Stenni, Barbara Werner, Martin Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
topic_facet |
geo envir |
description |
The Antarctic temperature changes over the past millennia remain more uncertain than in many other continental regions. This has several origins: (1) the number of high-resolution ice cores is small, in particular on the East Antarctic plateau and in some coastal areas in East Antarctica; (2) the short and spatially sparse instrumental records limit the calibration period for reconstructions and the assessment of the methodologies; (3) the link between isotope records from ice cores and local climate is usually complex and dependent on the spatial scales and timescales investigated. Here, we use climate model results, pseudoproxy experiments and data assimilation experiments to assess the potential for reconstructing the Antarctic temperature over the last 2 millennia based on a new database of stable oxygen isotopes in ice cores compiled in the framework of Antarctica2k (Stenni et al., 2017). The well-known covariance between δ18O and temperature is reproduced in the two isotope-enabled models used (ECHAM5/MPI-OM and ECHAM5-wiso), but is generally weak over the different Antarctic regions, limiting the skill of the reconstructions. Furthermore, the strength of the link displays large variations over the past millennium, further affecting the potential skill of temperature reconstructions based on statistical methods which rely on the assumption that the last decades are a good estimate for longer temperature reconstructions. Using a data assimilation technique allows, in theory, for changes in the δ18O–temperature link through time and space to be taken into account. Pseudoproxy experiments confirm the benefits of using data assimilation methods instead of statistical methods that provide reconstructions with unrealistic variances in some Antarctic subregions. They also confirm that the relatively weak link between both variables leads to a limited potential for reconstructing temperature based on δ18O. However, the reconstruction skill is higher and more uniform among reconstruction methods when the ... |
format |
Article in Journal/Newspaper |
author |
Klein, François Abram, Nerilie J. Curran, Mark A. J. Goosse, Hugues Goursaud, Sentia Masson-Delmotte, Valérie Moy, Andrew Neukom, Raphael Orsi, Anaïs Sjolte, Jesper Steiger, Nathan Stenni, Barbara Werner, Martin |
author_facet |
Klein, François Abram, Nerilie J. Curran, Mark A. J. Goosse, Hugues Goursaud, Sentia Masson-Delmotte, Valérie Moy, Andrew Neukom, Raphael Orsi, Anaïs Sjolte, Jesper Steiger, Nathan Stenni, Barbara Werner, Martin |
author_sort |
Klein, François |
title |
Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
title_short |
Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
title_full |
Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
title_fullStr |
Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
title_full_unstemmed |
Assessing the robustness of Antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
title_sort |
assessing the robustness of antarctic temperature reconstructions over the past 2 millennia using pseudoproxy and data assimilation experiments |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/cp-15-661-2019 https://cp.copernicus.org/articles/15/661/2019/ |
geographic |
Antarctic East Antarctica The Antarctic |
geographic_facet |
Antarctic East Antarctica The Antarctic |
genre |
Antarc* Antarctic Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica |
op_source |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-15-661-2019 10670/1.zyuovd 1814-9324 1814-9332 https://cp.copernicus.org/articles/15/661/2019/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-15-661-2019 |
container_title |
Climate of the Past |
container_volume |
15 |
container_issue |
2 |
container_start_page |
661 |
op_container_end_page |
684 |
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1766253482006806528 |