Borehole versus isotope temperatures on Greenland: Seasonality does matter

• Published in: Geophysical Research Letters
• Main Authors: Werner, Martin, Mikolajewicz, Uwe, Heimann, Martin, Hoffmann, Georg
• 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))
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2000
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Greenland; Ice Sheet
• Online Access: https://hal.science/hal-03123408; https://hal.science/hal-03123408/document; https://hal.science/hal-03123408/file/1999GL006075.pdf; https://doi.org/10.1029/1999GL006075

International audience New simulation results obtained with the Hamburg Atmosphere General Circulation Model ECHAM-4 under maximum glacial boundary (LGM) conditions confirm the paleotemperatures on Greenland determined by borehole thermometry. The disagreement between $•80 isotope based temperatures and the borehole temperatures of the LGM is not only reproduced by the model, but the simulation results provide a plausible explanation: Paleotemperatures inferred from $•80 measurements in ice cores are biased by a substantially increased seasonality of precipitation over Greenland during the LGM. During the glacial winter a much more zonal circulation prevents the effective transport of moisture to the Greenland ice sheet, and therefore reduces the contribution of isotopically strongly depleted winter snow to the annual mean isotope signal.