Retreat of the Greenland Ice Sheet During the Last Interglacial
Abstract
The Last Interglacial period (also known as the Eemian, ~129,000-116,000 years ago) experienced a warmer climate and a global mean sea level that reached ~6-9 m higher than present. In contrast to our current warming due to changes in atmospheric carbon dioxide and other greenhouse gases, the warming in this case was primarily due to the orbital configuration of the Earth leading to a high summer insolation anomaly in the northern hemisphere. Boreal forests extended northward, and this difference further enhanced the orbital warming in the Arctic. Paleoclimate proxy data suggest that the Greenland ice sheet retreated to a state smaller than its current extent, but did not collapse entirely. How much it contributed to sea level rise remains an open question, however, with previous estimates ranging from ~2-6 m.
To explore this problem, we use the Community Earth System Model to simulate the period from 127,000-121,000 years ago, allowing the Greenland ice sheet to evolve dynamically, coupled with global ocean, atmosphere, land, and sea ice component models. To conduct such a long transient simulation, we accelerate the orbital parameters and the ice sheet model with respect to the other components. The results of this simulation serve as the most realistic modeling estimate to date of the evolution of the Greenland ice sheet during the Last Interglacial, and our methodology is a step forward in conducting long transient simulations using a complex coupled Earth system model.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C11B..03S
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHERE;
- 1616 Climate variability;
- GLOBAL CHANGE;
- 1621 Cryospheric change;
- GLOBAL CHANGE;
- 1641 Sea level change;
- GLOBAL CHANGE