Modelling the evolution of the Antarctic ice sheet since the last interglacial
We present the effects of changing two sliding parameters, a deformational velocity parameter and two bedrock deflection parameters on the evolution of the Antarctic ice sheet over the period from the last interglacial until the present. These sensitivity experiments have been conducted by running t...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-07-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/8/1347/2014/tc-8-1347-2014.pdf |
| Summary: | We present the effects of changing two sliding parameters, a deformational
velocity parameter and two bedrock deflection parameters on the evolution of
the Antarctic ice sheet over the period from the last interglacial until the
present. These sensitivity experiments have been conducted by running the
dynamic ice model ANICE forward in time. The temporal climatological forcing is established by interpolating between two temporal climate states created with a
regional climate model. The interpolation is done in such a way
that both temperature and surface mass balance follow the European Project for Ice Coring in Antarctica (EPICA) Dome C
ice-core proxy record for temperature. We have determined an optimal set of
parameter values, for which a realistic grounding-line retreat history and
present-day ice sheet can be simulated; the simulation with this set of
parameter values is defined as the reference simulation. An increase of
sliding with respect to this reference simulation leads to a decrease of the
Antarctic ice volume due to enhanced ice velocities on mainly the West
Antarctic ice sheet. The effect of changing the deformational velocity
parameter mainly yields a change in east Antarctic ice volume. Furthermore,
we have found a minimum in the Antarctic ice volume during the mid-Holocene,
in accordance with observations. This is a robust feature in our model
results, where the strength and the timing of this minimum are both dependent
on the investigated parameters. More sliding and a slower responding bedrock
lead to a stronger minimum which emerges at an earlier time. From the model
results, we conclude that the Antarctic ice sheet has contributed
10.7 ± 1.3 m of eustatic sea level to the global ocean from the last
glacial maximum (about 16 ka for the Antarctic ice sheet) until the
present. |
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| ISSN: | 1994-0416 1994-0424 |