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| Titel |
Interdependence of the growth of the Northern Hemisphere ice sheets during the last glaciation: the role of atmospheric circulation |
| VerfasserIn |
P. Beghin, S. Charbit, C. Dumas, M. Kageyama, D. M. Roche, C. Ritz |
| 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 ; 10, no. 1 ; Nr. 10, no. 1 (2014-02-17), S.345-358 |
| Datensatznummer |
250116914
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| Publikation (Nr.) |
 copernicus.org/cp-10-345-2014.pdf |
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| Zusammenfassung |
| The development of large continental-scale ice sheets over Canada and
northern Europe during the last glacial cycle likely modified the track of
stationary waves and influenced the location of growing ice sheets through
changes in accumulation and temperature patterns. Although they are often
mentioned in the literature, these feedback mechanisms are poorly constrained
and have never been studied throughout an entire glacial–interglacial cycle.
Using the climate model of intermediate complexity CLIMBER-2 coupled with the
3-D ice-sheet model GRISLI (GRenoble Ice Shelf and Land Ice model), we investigate the impact of stationary waves on
the construction of past Northern Hemisphere ice sheets during the past
glaciation. The stationary waves are not explicitly computed in the model but
their effect on sea-level pressure is parameterized. We tested different
parameterizations to study separately the effect of surface temperature
(thermal forcing) and topography (orographic forcing) on sea-level pressure,
and therefore on atmospheric circulation and ice-sheet surface mass balance.
Our model results suggest that the response of ice sheets to thermal and/or
orographic forcings is rather different. At the beginning of the glaciation,
the orographic effect favors the growth of the Laurentide ice sheet, whereas
Fennoscandia appears rather sensitive to the thermal effect. Using the
ablation parameterization as a trigger to artificially modify the size of one
ice sheet, the remote influence of one ice sheet on the other is also studied
as a function of the stationary wave parameterizations. The sensitivity of
remote ice sheets is shown to be highly sensitive to the choice of these
parameterizations with a larger response when orographic effect is accounted
for. Results presented in this study suggest that the various spatial
distributions of ice sheets could be partly explained by the feedback
mechanisms occurring between ice sheets and atmospheric circulation. |
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