Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run
In this study, we use run-time bias correction to correct for the Action de Recherche Petite Echelle Grande Echelle (ARPEGE) atmospheric model systematic errors on large-scale atmospheric circulation. The bias-correction terms are built using the climatological mean of the adjustment terms on tenden...
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ftcopernicus:oai:publications.copernicus.org:tc90418 2023-05-15T13:24:14+02:00 Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run Beaumet, Julien Déqué, Michel Krinner, Gerhard Agosta, Cécile Alias, Antoinette Favier, Vincent 2021-08-06 application/pdf https://doi.org/10.5194/tc-15-3615-2021 https://tc.copernicus.org/articles/15/3615/2021/ eng eng doi:10.5194/tc-15-3615-2021 https://tc.copernicus.org/articles/15/3615/2021/ eISSN: 1994-0424 Text 2021 ftcopernicus https://doi.org/10.5194/tc-15-3615-2021 2021-08-09T16:22:27Z In this study, we use run-time bias correction to correct for the Action de Recherche Petite Echelle Grande Echelle (ARPEGE) atmospheric model systematic errors on large-scale atmospheric circulation. The bias-correction terms are built using the climatological mean of the adjustment terms on tendency errors in an ARPEGE simulation relaxed towards ERA-Interim reanalyses. The bias reduction with respect to the Atmospheric Model Intercomparison Project (AMIP)-style uncorrected control run for the general atmospheric circulation in the Southern Hemisphere is significant for mean state and daily variability. Comparisons for the Antarctic Ice Sheet with the polar-oriented regional atmospheric models MAR and RACMO2 and in situ observations also suggest substantial bias reduction for near-surface temperature and precipitation in coastal areas. Applying the method to climate projections for the late 21st century (2071–2100) leads to large differences in the projected changes of the atmospheric circulation in the southern high latitudes and of the Antarctic surface climate. The projected poleward shift and strengthening of the southern westerly winds are greatly reduced. These changes result in a significant 0.7 to 0.9 K additional warming and a 6 % to 9 % additional increase in precipitation over the grounded ice sheet. The sensitivity of precipitation increase to temperature increase ( +7.7 % K −1 and +9 % K −1 ) found is also higher than previous estimates. The highest additional warming rates are found over East Antarctica in summer. In winter, there is a dipole of weaker warming and weaker precipitation increase over West Antarctica, contrasted by a stronger warming and a concomitant stronger precipitation increase from Victoria to Adélie Land, associated with a weaker intensification of the Amundsen Sea Low. Text Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica Copernicus Publications: E-Journals Antarctic The Antarctic East Antarctica West Antarctica Amundsen Sea The Cryosphere 15 8 3615 3635 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
In this study, we use run-time bias correction to correct for the Action de Recherche Petite Echelle Grande Echelle (ARPEGE) atmospheric model systematic errors on large-scale atmospheric circulation. The bias-correction terms are built using the climatological mean of the adjustment terms on tendency errors in an ARPEGE simulation relaxed towards ERA-Interim reanalyses. The bias reduction with respect to the Atmospheric Model Intercomparison Project (AMIP)-style uncorrected control run for the general atmospheric circulation in the Southern Hemisphere is significant for mean state and daily variability. Comparisons for the Antarctic Ice Sheet with the polar-oriented regional atmospheric models MAR and RACMO2 and in situ observations also suggest substantial bias reduction for near-surface temperature and precipitation in coastal areas. Applying the method to climate projections for the late 21st century (2071–2100) leads to large differences in the projected changes of the atmospheric circulation in the southern high latitudes and of the Antarctic surface climate. The projected poleward shift and strengthening of the southern westerly winds are greatly reduced. These changes result in a significant 0.7 to 0.9 K additional warming and a 6 % to 9 % additional increase in precipitation over the grounded ice sheet. The sensitivity of precipitation increase to temperature increase ( +7.7 % K −1 and +9 % K −1 ) found is also higher than previous estimates. The highest additional warming rates are found over East Antarctica in summer. In winter, there is a dipole of weaker warming and weaker precipitation increase over West Antarctica, contrasted by a stronger warming and a concomitant stronger precipitation increase from Victoria to Adélie Land, associated with a weaker intensification of the Amundsen Sea Low. |
format |
Text |
author |
Beaumet, Julien Déqué, Michel Krinner, Gerhard Agosta, Cécile Alias, Antoinette Favier, Vincent |
spellingShingle |
Beaumet, Julien Déqué, Michel Krinner, Gerhard Agosta, Cécile Alias, Antoinette Favier, Vincent Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run |
author_facet |
Beaumet, Julien Déqué, Michel Krinner, Gerhard Agosta, Cécile Alias, Antoinette Favier, Vincent |
author_sort |
Beaumet, Julien |
title |
Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run |
title_short |
Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run |
title_full |
Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run |
title_fullStr |
Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run |
title_full_unstemmed |
Significant additional Antarctic warming in atmospheric bias-corrected ARPEGE projections with respect to control run |
title_sort |
significant additional antarctic warming in atmospheric bias-corrected arpege projections with respect to control run |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-3615-2021 https://tc.copernicus.org/articles/15/3615/2021/ |
geographic |
Antarctic The Antarctic East Antarctica West Antarctica Amundsen Sea |
geographic_facet |
Antarctic The Antarctic East Antarctica West Antarctica Amundsen Sea |
genre |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-15-3615-2021 https://tc.copernicus.org/articles/15/3615/2021/ |
op_doi |
https://doi.org/10.5194/tc-15-3615-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
8 |
container_start_page |
3615 |
op_container_end_page |
3635 |
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1766378182203670528 |