Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries
Ice cores are an important record of the past surface mass balance (SMB) of ice sheets, with SMB mitigating the ice sheets’ sea level impact over the recent decades. For the Antarctic Ice Sheet (AIS), SMB is dominated by largescale atmospheric circulation, which collects warm moist air from furthe...
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Online Access: | http://hdl.handle.net/2078.1/238483 https://doi.org/10.5194/tc-14-4083-2020 |
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ftunivlouvain:oai:dial.uclouvain.be:boreal:238483 2024-05-12T07:55:08+00:00 Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries Cavitte, Marie Dalaiden, Quentin Goosse, Hugues Lenaerts, Jan Thomas, Elizabeth UCL - SST/ELI/ELIC - Earth & Climate 2020 http://hdl.handle.net/2078.1/238483 https://doi.org/10.5194/tc-14-4083-2020 eng eng Copernicus GmbH boreal:238483 http://hdl.handle.net/2078.1/238483 doi:10.5194/tc-14-4083-2020 urn:ISSN:1994-0416 urn:EISSN:1994-0424 info:eu-repo/semantics/openAccess The Cryosphere, Vol. 14, no.11, p. 4083-4102 (2020) Earth-Surface Processes Water Science and Technology info:eu-repo/semantics/article 2020 ftunivlouvain https://doi.org/10.5194/tc-14-4083-2020 2024-04-17T16:42:32Z Ice cores are an important record of the past surface mass balance (SMB) of ice sheets, with SMB mitigating the ice sheets’ sea level impact over the recent decades. For the Antarctic Ice Sheet (AIS), SMB is dominated by largescale atmospheric circulation, which collects warm moist air from further north and releases it in the form of snow as widespread accumulation or focused atmospheric rivers on the continent. This suggests that the snow deposited at the surface of the AIS should record strongly coupled SMB and surface air temperature (SAT) variations. Ice cores use δ 18O as a proxy for SAT as they do not record SAT directly. Here, using isotope-enabled global climate models and the RACMO2.3 regional climate model, we calculate positive SMB–SAT and SMB–δ 18O annual correlations over ∼ 90 % of the AIS. The high spatial resolution of the RACMO2.3 model allows us to highlight a number of areas where SMB and SAT are not correlated, and we show that wind-driven processes acting locally, such as foehn and katabatic effects, can overwhelm the large-scale atmospheric contribution in SMB and SAT responsible for the positive SMB–SAT annual correlations. We focus in particular on Dronning Maud Land, East Antarctica, where the ice promontories clearly show these wind-induced effects. However, using the PAGES2k ice core compilations of SMB and δ 18O of Thomas et al. (2017) and Stenni et al. (2017), we obtain a weak annual correlation, on the order of 0.1, between SMB and δ 18O over the past ∼ 150 years. We obtain an equivalently weak annual correlation between ice core SMB and the SAT reconstruction of Nicolas and Bromwich (2014) over the past ∼ 50 years, although the ice core sites are not spatially co-located with the areas displaying a low SMB–SAT annual correlation in the models. To resolve the discrepancy between the measured and modeled signals, we show that averaging the ice core records in close spatial proximity increases their SMB–SAT annual correlation. This increase shows that the weak ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica ice core Ice Sheet The Cryosphere DIAL@UCLouvain (Université catholique de Louvain) Antarctic The Antarctic East Antarctica Dronning Maud Land The Cryosphere 14 11 4083 4102 |
institution |
Open Polar |
collection |
DIAL@UCLouvain (Université catholique de Louvain) |
op_collection_id |
ftunivlouvain |
language |
English |
topic |
Earth-Surface Processes Water Science and Technology |
spellingShingle |
Earth-Surface Processes Water Science and Technology Cavitte, Marie Dalaiden, Quentin Goosse, Hugues Lenaerts, Jan Thomas, Elizabeth Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries |
topic_facet |
Earth-Surface Processes Water Science and Technology |
description |
Ice cores are an important record of the past surface mass balance (SMB) of ice sheets, with SMB mitigating the ice sheets’ sea level impact over the recent decades. For the Antarctic Ice Sheet (AIS), SMB is dominated by largescale atmospheric circulation, which collects warm moist air from further north and releases it in the form of snow as widespread accumulation or focused atmospheric rivers on the continent. This suggests that the snow deposited at the surface of the AIS should record strongly coupled SMB and surface air temperature (SAT) variations. Ice cores use δ 18O as a proxy for SAT as they do not record SAT directly. Here, using isotope-enabled global climate models and the RACMO2.3 regional climate model, we calculate positive SMB–SAT and SMB–δ 18O annual correlations over ∼ 90 % of the AIS. The high spatial resolution of the RACMO2.3 model allows us to highlight a number of areas where SMB and SAT are not correlated, and we show that wind-driven processes acting locally, such as foehn and katabatic effects, can overwhelm the large-scale atmospheric contribution in SMB and SAT responsible for the positive SMB–SAT annual correlations. We focus in particular on Dronning Maud Land, East Antarctica, where the ice promontories clearly show these wind-induced effects. However, using the PAGES2k ice core compilations of SMB and δ 18O of Thomas et al. (2017) and Stenni et al. (2017), we obtain a weak annual correlation, on the order of 0.1, between SMB and δ 18O over the past ∼ 150 years. We obtain an equivalently weak annual correlation between ice core SMB and the SAT reconstruction of Nicolas and Bromwich (2014) over the past ∼ 50 years, although the ice core sites are not spatially co-located with the areas displaying a low SMB–SAT annual correlation in the models. To resolve the discrepancy between the measured and modeled signals, we show that averaging the ice core records in close spatial proximity increases their SMB–SAT annual correlation. This increase shows that the weak ... |
author2 |
UCL - SST/ELI/ELIC - Earth & Climate |
format |
Article in Journal/Newspaper |
author |
Cavitte, Marie Dalaiden, Quentin Goosse, Hugues Lenaerts, Jan Thomas, Elizabeth |
author_facet |
Cavitte, Marie Dalaiden, Quentin Goosse, Hugues Lenaerts, Jan Thomas, Elizabeth |
author_sort |
Cavitte, Marie |
title |
Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries |
title_short |
Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries |
title_full |
Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries |
title_fullStr |
Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries |
title_full_unstemmed |
Reconciling the surface temperature–surface mass balance relationship in models and ice cores in Antarctica over the last 2 centuries |
title_sort |
reconciling the surface temperature–surface mass balance relationship in models and ice cores in antarctica over the last 2 centuries |
publisher |
Copernicus GmbH |
publishDate |
2020 |
url |
http://hdl.handle.net/2078.1/238483 https://doi.org/10.5194/tc-14-4083-2020 |
geographic |
Antarctic The Antarctic East Antarctica Dronning Maud Land |
geographic_facet |
Antarctic The Antarctic East Antarctica Dronning Maud Land |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica ice core Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica ice core Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol. 14, no.11, p. 4083-4102 (2020) |
op_relation |
boreal:238483 http://hdl.handle.net/2078.1/238483 doi:10.5194/tc-14-4083-2020 urn:ISSN:1994-0416 urn:EISSN:1994-0424 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-14-4083-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
11 |
container_start_page |
4083 |
op_container_end_page |
4102 |
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1798834228089061376 |