How warm was Greenland during the last interglacial period?

• Published in: Climate of the Past
• Main Authors: LANDAIS, AMAELLE, Masson-Delmotte, Valérie, Capron, Emilie, Langebroek, Petra M., Bakker, Pepijn, Stone, Emma J., Merz, Niklaus, Raible, Christoph C., Fischer, Hubertus, Orsi, Anaïs, Prié, Frédéric, Vinther, Bo, Dahl-Jensen, Dorthe
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Life Sciences Amsterdam (MAC4), Centrum Wiskunde & Informatica (CWI), California Institute of Technology (CALTECH), Universität Bern Bern, Centre for Ice and Climate Copenhagen, Niels Bohr Institute Copenhagen (NBI), Faculty of Science Copenhagen, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science Copenhagen, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarctic; Greenland; Antarc*; Greenland ice core; Greenland Ice core Project; ice core; Ice Sheet; NGRIP; North Greenland; North Greenland Ice Core Project; Sea ice
• Online Access: https://hal.archives-ouvertes.fr/hal-01587491; https://hal.archives-ouvertes.fr/hal-01587491/document; https://hal.archives-ouvertes.fr/hal-01587491/file/cp-12-1933-2016.pdf; https://doi.org/10.5194/cp-12-1933-2016

International audience The last interglacial period (LIG, ∼ 129-116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 • C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning , suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Green-land surface warming using ice core air isotopic composition (δ 15 N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 • C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 • C warming initially determined from NEEM water isotopes but at the upper end of the preindus-trial period to LIG temperature difference of +5.2 ± 2.3 • C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 • C) are produced in response to prescribed changes in sea ice extent and ice sheet topography .