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| Titel |
Simulated Greenland evolution during the Eemian and MIS 11 interglacials |
| VerfasserIn |
Reinhard Calov, Alex Robinson, Andrey Ganopolski |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047299
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| Zusammenfassung |
| Gaining insight into the long-term change of Greenland ice volume is important for
understanding the future rise of sea level due to global warming. Here, we compare the
reduction in simulated ice volume of the Greenland ice sheet (GIS) during the Eemian with
that during MIS 11. The MIS 11 period is very interesting, because it is potentially the most
recent time when Greenland was mostly ice free. This hypothesis is supported by
DNA found at Dye-3 indicating the existence of boreal forest there around the time
period of MIS 11. Therefore, simulations of MIS 11 combined with paleo data
could help to validate model parameters. For the simulations, we utilize the regional
energy-moisture balance model REMBO bi-directionally coupled to the polythermal ice
sheet model SICOPOLIS, and forced with anomaly fields computed by the Earth
system model of intermediate complexity CLIMBER-2. CLIMBER-2 is forced
by isolation and atmospheric CO2 over past eight glacial cycles and realistically
simulates the evolution of the northern Hemisphere ice sheets and global climate. We
use the temperature anomaly from CLIMBER-2 as external forcing for REMBO,
along with insolation, CO2 and sea level changes. In order to span the potential
uncertainty in temperature changes and surface mass balance during MIS 11, we perform
an ensemble of simulation by scaling the positive temperature anomaly during
interglacial by factors ranging from 0.5 to 2 and by varying a free parameter in the
surface melt scheme (within a constrained range found in a previous study). We
present a detailed comparison of the simulated Greenland ice volume during the
Eemian and MIS 11. While Greenland’s melt during the Eemian is equally driven by
temperature and insolation, the temperature plays a more important role for the melt of the
GIS during MIS 11. In general, we found a stronger reduction in Greenland ice
volume during MIS 11 than during the Eemian, in spite of much higher boreal
summer insolation during Eemian. The simple explanation for this result is that
warm climate conditions during MIS 11 lasted much longer than during Eemian
interglacial. |
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