title: Greenland temperature response to climate forcing during the last deglaciation.
abstract: Greenland ice core water isotopic composition (δ(18)O) provides detailed evidence for abrupt climate changes but is by itself insufficient for quantitative reconstruction of past temperatures and their spatial patterns. We investigate Greenland temperature evolution during the last deglaciation using independent reconstructions from three ice cores and simulations with a coupled ocean-atmosphere climate model. Contrary to the traditional δ(18)O interpretation, the Younger Dryas period was 4.5° ± 2°C warmer than the Oldest Dryas, due to increased carbon dioxide forcing and summer insolation. The magnitude of abrupt temperature changes is larger in central Greenland (9° to 14°C) than in the northwest (5° to 9°C), fingerprinting a North Atlantic origin. Simulated changes in temperature seasonality closely track changes in the Atlantic overturning strength and support the hypothesis that abrupt climate change is mostly a winter phenomenon.
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA. buizertc@science.oregonstate.edu.
authors.forename: Christo
authors.initials: C
authors.lastname: Buizert
authors.affiliation: Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark. Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Gkinis
authors.affiliation: Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA 92093, USA.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Severinghaus
authors.affiliation: Center for Climatic Research, Nelson Institute for Environmental Studies, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.affiliation: Department of Physics and Physical Oceanography, Memorial University, St. John's, Canada.
authors.forename: Benoit S
authors.initials: BS
authors.lastname: Lecavalier
authors.affiliation: Division of Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Kindler
authors.affiliation: Division of Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Leuenberger
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Anders E
authors.initials: AE
authors.lastname: Carlson
authors.affiliation: Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark.
authors.forename: Bo
authors.initials: B
authors.lastname: Vinther
authors.affiliation: Laboratoire des Sciences du Climat et de l'Environnement, Institut Pierre Simon Laplace (UMR CEA-CNRS-UVSQ 8212), Gif-sur-Yvette, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Masson-Delmotte
authors.affiliation: Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA.
authors.forename: James W C
authors.initials: JW
authors.lastname: White
authors.affiliation: Center for Climatic Research, Nelson Institute for Environmental Studies, University of Wisconsin, Madison, WI 53706, USA. Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing 100871, China.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO 80307, USA.
authors.forename: Bette
authors.initials: B
authors.lastname: Otto-Bliesner
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Brook
mesh_terms: D057231:Climate Change; D003198:Computer Simulation; D005615:Freezing; D006116:Greenland; D046448:Ice Cover; D008962:Models, Theoretical; D010103:Oxygen Isotopes / Q000032:analysis; D013696:Temperature
chemical_list: D010103:Oxygen Isotopes