From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model
>Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermomechanically coupled model on 1 km horizontal re...
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ftdatacite:10.34657/3781 2023-05-15T13:45:09+02:00 From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model Feldmann, J. Levermann, A. 2017 https://dx.doi.org/10.34657/3781 https://oa.tib.eu/renate/handle/123456789/5152 en eng Göttingen : Copernicus GmbH Creative Commons Attribution 3.0 Unported CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Parallel Ice Sheet Model ice-sheet-shelf system instability 550 article-journal ScholarlyArticle article Text 2017 ftdatacite https://doi.org/10.34657/3781 2022-04-01T09:37:59Z >Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermomechanically coupled model on 1 km horizontal resolution includes an enthalpy-based formulation of the thermodynamics, a nonlinear stress-balance-based sliding law and a very simple subglacial hydrology. The simulated unforced surging is characterized by rapid ice streaming through a bed trough, resulting in abrupt discharge of ice across the grounding line which is eventually calved into the ocean. We visualize the central feedbacks that dominate the subsequent phases of ice buildup, surge and stabilization which emerge from the interaction between ice dynamics, thermodynamics and the subglacial till layer. Results from the variation of surface mass balance and basal roughness suggest that ice sheets of medium thickness may be more susceptible to surging than relatively thin or thick ones for which the surge feedback loop is damped. We also investigate the influence of different basal sliding laws (ranging from purely plastic to nonlinear to linear) on possible surging. The presented mechanisms underlying our simulations of self-maintained, periodic ice growth and destabilization may play a role in large-scale ice-sheet surging, such as the surging of the Laurentide Ice Sheet, which is associated with Heinrich events, and ice-stream shutdown and reactivation, such as observed in the Siple Coast region of West Antarctica. Text Antarc* Antarctica Ice Sheet West Antarctica DataCite Metadata Store (German National Library of Science and Technology) West Antarctica Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Parallel Ice Sheet Model ice-sheet-shelf system instability 550 |
spellingShingle |
Parallel Ice Sheet Model ice-sheet-shelf system instability 550 Feldmann, J. Levermann, A. From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model |
topic_facet |
Parallel Ice Sheet Model ice-sheet-shelf system instability 550 |
description |
>Here we report on a cyclic, physical ice-discharge instability in the Parallel Ice Sheet Model, simulating the flow of a three-dimensional, inherently buttressed ice-sheet-shelf system which periodically surges on a millennial timescale. The thermomechanically coupled model on 1 km horizontal resolution includes an enthalpy-based formulation of the thermodynamics, a nonlinear stress-balance-based sliding law and a very simple subglacial hydrology. The simulated unforced surging is characterized by rapid ice streaming through a bed trough, resulting in abrupt discharge of ice across the grounding line which is eventually calved into the ocean. We visualize the central feedbacks that dominate the subsequent phases of ice buildup, surge and stabilization which emerge from the interaction between ice dynamics, thermodynamics and the subglacial till layer. Results from the variation of surface mass balance and basal roughness suggest that ice sheets of medium thickness may be more susceptible to surging than relatively thin or thick ones for which the surge feedback loop is damped. We also investigate the influence of different basal sliding laws (ranging from purely plastic to nonlinear to linear) on possible surging. The presented mechanisms underlying our simulations of self-maintained, periodic ice growth and destabilization may play a role in large-scale ice-sheet surging, such as the surging of the Laurentide Ice Sheet, which is associated with Heinrich events, and ice-stream shutdown and reactivation, such as observed in the Siple Coast region of West Antarctica. |
format |
Text |
author |
Feldmann, J. Levermann, A. |
author_facet |
Feldmann, J. Levermann, A. |
author_sort |
Feldmann, J. |
title |
From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model |
title_short |
From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model |
title_full |
From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model |
title_fullStr |
From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model |
title_full_unstemmed |
From cyclic ice streaming to Heinrich-like events: The grow-And-surge instability in the Parallel Ice Sheet Model |
title_sort |
from cyclic ice streaming to heinrich-like events: the grow-and-surge instability in the parallel ice sheet model |
publisher |
Göttingen : Copernicus GmbH |
publishDate |
2017 |
url |
https://dx.doi.org/10.34657/3781 https://oa.tib.eu/renate/handle/123456789/5152 |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
West Antarctica Siple Siple Coast |
geographic_facet |
West Antarctica Siple Siple Coast |
genre |
Antarc* Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet West Antarctica |
op_rights |
Creative Commons Attribution 3.0 Unported CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.34657/3781 |
_version_ |
1766213822303961088 |