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| Titel |
Numerical reconstructions of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle |
| VerfasserIn |
S. Charbit, C. Ritz, G. Philippon, V. Peyaud, M. Kageyama |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 3, no. 1 ; Nr. 3, no. 1 (2007-01-26), S.15-37 |
| Datensatznummer |
250000738
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| Publikation (Nr.) |
 copernicus.org/cp-3-15-2007.pdf |
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| Zusammenfassung |
| A 3-dimensional thermo-mechanical ice-sheet model is used to simulate the
evolution of the Northern Hemisphere ice sheets through the last
glacial-interglacial cycle. The ice-sheet model is forced by the results
from six different atmospheric general circulation models (AGCMs). The
climate evolution over the period under study is reconstructed using two
climate equilibrium simulations performed for the Last Glacial Maximum (LGM)
and for the present-day periods and an interpolation through time between
these snapshots using a glacial index calibrated against the GRIP
δ18O record. Since it is driven by the timing of the GRIP signal, the
temporal evolution of the ice volume and the ice-covered area is
approximately the same from one simulation to the other. However, both ice
volume curves and spatial distributions of the ice sheets present some major
differences from one AGCM forcing to the other. The origin of these
differences, which are most visible in the maximum amplitude of the ice
volume, is analyzed in terms of differences in climate forcing. This
analysis allows for a partial evaluation of the ability of GCMs to simulate
climates consistent with the reconstructions of past ice sheets. Although
some models properly reproduce the advance or retreat of ice sheets in some
specific areas, none of them is able to reproduce both North American or
Eurasian ice complexes in full agreement with observed sea-level variations
and geological data. These deviations can be attributed to shortcomings in
the climate forcing and in the LGM ice-sheet reconstruction used as a
boundary condition for GCM runs, but also to missing processes in the
ice-sheet model itself. |
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