HR: 1340h
AN: U43A-0860    [Abstracts]
TI: What can be learnt from the comparison between ice core temperature records and climate model simulations?
AU: * Masson-Delmotte, V
EM: valerie.masson@cea.fr
AF: LSCE (CEA-CNRS-UVSQ-IPSL), Bat 701 L'Orme des Merisiers CEA Saclay, Gif sur Yvette, 91 191, France
AB: Past temperature reconstructions are available from Greenland and Antarctica using different temperature reconstruction methods applied on ice cores and boreholes. Here we focus on two time periods : (i) the temperature increase from the Last Glacial Maximum to present-day, (ii) the temperature difference between the last interglacial period and present-day. For these two periods, ice-core data are compared to the magnitude of temperature change simulated for central Greenland and central eastern Antarctica by coupled ocean-atmosphere state-of-the-art climate models. Model-data comparisons suggest that glacial-interglacial temperature changes in Antarctica may have global relevance in terms of climate sensitivity. These comparisons further show that climate models may under- estimate the polar warming, possibly due to missing past forcings such as those associated with land surface and dust changes. For the last interglacial period, ice cores show that Greenland and Antarctica were significantly warmer than during the late Holocene -although with probably different optima periods. In response to the 130 ka or 125 ka BP orbital forcing, state-of-the-art climate models fail to capture the reconstructed Antarctic warming, which raises questions regarding the mechanisms linking past Antarctic and northern hemisphere climate variations.
DE: 0724 Ice cores (4932)
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 4926 Glacial
DE: 4936 Interglacial
SC: Union [U]
MN: 2007 Fall Meeting