Spatial patterns of multi–centennial surface air temperature trends in Antarctica over 1–1000 CE: Insights from ice core records and modeling

• Published in: Quaternary Science Reviews
• Main Authors: Lyu, Zhiqiang, Goosse, Hugues, Dalaiden, Quentin, Klein, François, Shi, Feng, Wagner, Sebastian, Braconnot, Pascale
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), IGGCAS-201905; Université Catholique de Louvain; Fonds De La Recherche Scientifique - FNRS, FNRS; Belgian Federal Science Policy Office, BELSPO: BR/165/A2/Mass2Ant; China Scholarship Council, CSC; Youth Innovation Promotion Association of the Chinese Academy of Sciences, YIPA CAS; Université Catholique de Louvain, UCL, We acknowledge the World Climate Research Programme Working Group on Coupled Modeling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model outputs. This work was supported by the Belgian Research Action through Interdisciplinary Networks (BRAIN–be) from the Belgian Science Policy Office in the framework of the “East Antarctic surface mass balance in the Anthropocene: observations and multiscale modeling (Mass2Ant)” project (contract no. BR/165/A2/Mass2Ant). Zhiqiang Lyu is supported by China Scholarship Council (CSC) – Université catholique de Louvain Co–Funding. Hugues Goosse is the research director within the F.R.S.–FNRS. Feng Shi is funded by the Youth Innovation Promotion Association CAS and the Key Research Program of the Institute of Geology & Geophysics , CAS (Grant No. IGGCAS-201905 ). Computational resources have been provided by the supercomputing facilities of the Université catholique de Louvain (CISM/UCL) and the Consortium des Équipements de Calcul Intensif en Fédération Wallonie Bruxelles ( CÉCI ) funded by the Fond de la Recherche Scientifique de Belgique (F.R.S.–FNRS) under convention 2.5020.11 ., We acknowledge the World Climate Research Programme Working Group on Coupled Modeling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model outputs. This work was supported by the Belgian Research Action through Interdisciplinary Networks (BRAIN?be) from the Belgian Science Policy Office in the framework of the ?East Antarctic surface mass balance in the Anthropocene: observations and multiscale modeling (Mass2Ant)? project (contract no. BR/165/A2/Mass2Ant). Zhiqiang Lyu is supported by China Scholarship Council (CSC) ? Universit? catholique de Louvain Co?Funding. Hugues Goosse is the research director within the F.R.S.?FNRS. Feng Shi is funded by the Youth Innovation Promotion Association CAS and the Key Research Program of the Institute of Geology & Geophysics, CAS (Grant No. IGGCAS-201905). Computational resources have been provided by the supercomputing facilities of the Universit? catholique de Louvain (CISM/UCL) and the Consortium des ?quipements de Calcul Intensif en F?d?ration Wallonie Bruxelles (C?CI) funded by the Fond de la Recherche Scientifique de Belgique (F.R.S.?FNRS) under convention 2.5020.11.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Antarctica; Data assimilation; First millennium; Reconstruction; Spatial pattern; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Amundsen Sea; Antarctic; East Antarctica; Antarc*; ice core
• Online Access: https://hal.archives-ouvertes.fr/hal-03434928; https://doi.org/10.1016/j.quascirev.2021.107205

International audience The spatial pattern of Antarctic surface air temperature variability on multi–decadal to multi–centennial time scales is poorly known because of the short instrumental records, the relatively small number of high–resolution paleoclimate observations, and biases in climate models. Here, changes in surface air temperature over Antarctica are reconstructed over the past two millennia using data assimilation constrained by different ice core water isotope records in order to identify robust signals. The comparison between previous statistically based temperature reconstructions and simulations covering the full Common Era driven by natural and anthropogenic forcings shows major discrepancies occurring in the period 1–1000 CE over East Antarctica, with the reconstructions displaying a warming over 1–500 CE that is not reproduced by the simulations. This suggests that the trends in the first millennium deduced from the statistically based reconstructions are unlikely to be entirely forced by external forcings. Our reconstructions show the high sensitivity of the 500-year temperature trend in Antarctica and its spatial distribution to selection of the records for the reconstructions, especially during 1–500 CE. A robust cooling over Antarctica during 501–1000 CE has been obtained in three data assimilation–based reconstructions with a larger magnitude in the WAIS than elsewhere over Antarctica, in agreement with previous estimates with the larger changes than simulated in climate models. The reconstructions for atmospheric circulation indicate that the pattern of temperature changes over 501–1000 CE is related to the positive trend of Southern Annular Mode and a deepening of Amundsen Sea Low. This confirms the role of internal variability in the temperature trends on multi–centennial scales.