Abstract
Abstract. We compare the present and last interglacial periods as recorded in Antarctic water stable isotope records now available at various temporal resolutions from six East Antarctic ice cores: Vostok, Taylor Dome, EPICA Dome C (EDC), EPICA Dronning Maud Land (EDML), Dome Fuji and the recent TALDICE ice core from Talos Dome. We first review the different modern site characteristics in terms of ice flow, meteorological conditions, precipitation intermittency and moisture origin, as depicted by meteorological data, atmospheric reanalyses and Lagrangian moisture source diagnostics. These different factors can indeed alter the relationships between temperature and water stable isotopes. Using five records with sufficient resolution on the EDC3 age scale, common features are quantified through principal component analyses. Consistent with instrumental records and atmospheric model results, the ice core data depict rather coherent and homogenous patterns in East Antarctica during the last two interglacials. Across the East Antarctic plateau, regional differences, with respect to the common East Antarctic signal, appear to have similar patterns during the current and last interglacials. We identify two abrupt shifts in isotopic records during the glacial inception at TALDICE and EDML, likely caused by regional sea ice expansion. These regional differences are discussed in terms of moisture origin and in terms of past changes in local elevation histories, which are compared to ice sheet model results. Our results suggest that elevation changes may contribute significantly to inter-site differences. These elevation changes may be underestimated by current ice sheet models.
Highlights
In the context of global warming, documenting past natural climatic variability in polar regions offers a benchmark against which to test Earth system models (Masson-Delmotte et al, 2006b)
We note that an increased CO2 warming scenario is an imperfect analogue for the boundary conditions of past interglacials. It has been argued (Masson et al, 2000; Masson-Delmotte et al, 2010a) that the early Holocene and last interglacial optima recorded in EPICA Dome C isotopic records are caused by a bipolar see-saw pattern occurring under interglacial contexts and caused by the Northern Hemisphere ice sheet deglacial history, to glacial Antarctic Isotopic Maxima (Capron et al, 2010)
The results suggest that, during interglacial periods, this precipitation intermittency effect can be different among sites on the East Antarctic plateau, and between the East Antarctic plateau and the Taylor Dome ice core (TD)/Talos Dome ice core (TALDICE) area
Summary
In the context of global warming, documenting past natural climatic variability in polar regions offers a benchmark against which to test Earth system models (Masson-Delmotte et al, 2006b).
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