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| Titel |
Interaction of ice sheets and climate during the past 800 000 years |
| VerfasserIn |
L. B. Stap, R. S. W. van de Wal, B. de Boer, R. Bintanja, L. J. Lourens |
| 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. 6 ; Nr. 10, no. 6 (2014-12-04), S.2135-2152 |
| Datensatznummer |
250117083
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| Publikation (Nr.) |
 copernicus.org/cp-10-2135-2014.pdf |
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| Zusammenfassung |
During the Cenozoic, land ice and climate interacted on many
different timescales. On long timescales, the effect of land ice
on global climate and sea level is mainly set by large ice sheets in
North America, Eurasia, Greenland and Antarctica. The climatic
forcing of these ice sheets is largely determined by the meridional
temperature profile resulting from radiation and greenhouse gas
(GHG) forcing. As a response, the ice sheets cause an increase in
albedo and surface elevation, which operates as a feedback in the
climate system. To quantify the importance of these climate–land
ice processes, a zonally averaged energy balance climate model is
coupled to five one-dimensional ice sheet models, representing the
major ice sheets.
In this study, we focus on the transient simulation of the past
800 000 years, where a high-confidence CO2 record
from ice core samples is used as input in combination with
Milankovitch radiation changes. We obtain simulations of
atmospheric temperature, ice volume and sea level that are in good
agreement with recent proxy-data reconstructions. We examine
long-term climate–ice-sheet interactions by a comparison of
simulations with uncoupled and coupled ice sheets. We show that
these interactions amplify global temperature anomalies by up to
a factor of 2.6, and that they increase polar amplification by
94%. We demonstrate that, on these long timescales, the
ice-albedo feedback has a larger and more global influence on the
meridional atmospheric temperature profile than the surface-height-temperature feedback. Furthermore, we assess the influence of
CO2 and insolation by performing runs with one or both of
these variables held constant. We find that atmospheric temperature
is controlled by a complex interaction of CO2 and
insolation, and both variables serve as thresholds for northern
hemispheric glaciation. |
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