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| Titel |
Simulating Heinrich events in a coupled atmosphere-ocean-ice sheet model |
| VerfasserIn |
Uwe Mikolajewicz, Florian Ziemen |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250124807
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| Publikation (Nr.) |
 EGU/EGU2016-4296.pdf |
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| Zusammenfassung |
| Heinrich events are among the most prominent events of long-term climate variability
recorded in proxies across the northern hemisphere. They are the archetype of ice sheet –
climate interactions on millennial time scales. Nevertheless, the exact mechanisms that cause
Heinrich events are still under discussion, and their climatic consequences are far from
being fully understood. We contribute to answering the open questions by studying
Heinrich events in a coupled ice sheet model (ISM) atmosphere-ocean-vegetation
general circulation model (AOVGCM) framework, where this variability occurs
as part of the model generated internal variability without the need to prescribe
external perturbations, as was the standard approach in almost all model studies so
far.
The setup consists of a northern hemisphere setup of the modified Parallel Ice Sheet Model
(mPISM) coupled to the global coarse resolution AOVGCM ECHAM5/MPIOM/LPJ. The
simulations used for this analysis were an ensemble covering substantial parts of the late
Glacial forced with transient insolation and prescribed atmospheric greenhouse gas
concentrations.
The modeled Heinrich events show a marked influence of the ice discharge on the Atlantic
circulation and heat transport, but none of the Heinrich events during the Glacial did show a
complete collapse of the North Atlantic meridional overturning circulation. The simulated
main consequences of the Heinrich events are a freshening and cooling over the North
Atlantic and a drying over northern Europe. |
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