Sensitivity of interglacial Greenland temperature and δ18O: ice core data, orbital and increased CO2 climate simulations

• Published in: Climate of the Past
• Main Authors: Masson-Delmotte, Valérie, Braconnot, P., Hoffmann, G., Jouzel, J., Kageyama, M., Landais, A., Lejeune, Q., Risi, C., Sime, L., Sjolte, J., Swingedouw, D., Vinther, B.
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), 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)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Modélisation du climat (CLIM), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder -National Oceanic and Atmospheric Administration (NOAA), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Niels Bohr Institute Copenhagen (NBI), Faculty of Science Copenhagen, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Arctic; Greenland; Greenland ice cores; ice core; Ice Sheet
• Online Access: https://hal.science/hal-02931773; https://hal.science/hal-02931773/document; https://hal.science/hal-02931773/file/cp-7-1041-2011.pdf; https://doi.org/10.5194/cp-7-1041-2011

International audience The sensitivity of interglacial Greenland temperature to orbital and CO 2 forcing is investigated using the NorthGRIP ice core data and coupled ocean-atmosphere IPSL-CM4 model simulations. These simulations were conducted in response to different interglacial orbital configurations , and to increased CO 2 concentrations. These different forcings cause very distinct simulated seasonal and lat-itudinal temperature and water cycle changes, limiting the analogies between the last interglacial and future climate. However, the IPSL-CM4 model shows similar magnitudes of Arctic summer warming and climate feedbacks in response to 2 × CO 2 and orbital forcing of the last interglacial period (126 000 years ago). The IPSL-CM4 model produces a remarkably linear relationship between TOA incoming summer solar radiation and simulated changes in summer and annual mean central Greenland temperature. This contrasts with the stable isotope record from the Greenland ice cores, showing a multi-millennial lagged response to summer insolation. During the early part of interglacials, the observed lags may be explained by ice sheet-ocean feedbacks linked with changes in ice sheet elevation and the impact of meltwater on ocean circulation , as investigated with sensitivity studies. A quantitative comparison between ice core data and climate simulations requires stability of the stable isotope-temperature relationship to be explored. Atmospheric simulations including water stable isotopes have been conducted with the LMDZiso model under different boundary conditions. This set of simulations allows calculation of a temporal Correspondence to: V. Masson-Delmotte ([e-mail]) Greenland isotope-temperature slope (0.3-0.4 ‰ per • C) during warmer-than-present Arctic climates, in response to increased CO 2 , increased ocean temperature and orbital forcing. This temporal slope appears half as large as the modern spatial gradient and is consistent with other ice core estimates. It may, however, be ...