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 resolu...
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München : European Geopyhsical Union
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ftleibnizopen:oai:oai.leibnizopen.de:ISaOVYsBBwLIz6xGlOdE 2023-11-12T04:02:49+01:00 From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the parallel ice sheet model Feldmann, Johannes Levermann, Anders 2017 application/pdf https://doi.org/10.34657/966 https://oa.tib.eu/renate/handle/123456789/953 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ The Cryosphere, Volume 11, Issue 4, Page 1913-1932 550 article Text 2017 ftleibnizopen https://doi.org/10.34657/966 2023-10-22T23:27:09Z 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. publishedVersion Article in Journal/Newspaper Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica Unknown Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) West Antarctica |
institution |
Open Polar |
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Unknown |
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ftleibnizopen |
language |
English |
topic |
550 |
spellingShingle |
550 Feldmann, Johannes Levermann, Anders From cyclic ice streaming to Heinrich-like events: the grow-and-surge instability in the parallel ice sheet model |
topic_facet |
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. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Feldmann, Johannes Levermann, Anders |
author_facet |
Feldmann, Johannes Levermann, Anders |
author_sort |
Feldmann, Johannes |
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 |
München : European Geopyhsical Union |
publishDate |
2017 |
url |
https://doi.org/10.34657/966 https://oa.tib.eu/renate/handle/123456789/953 |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
Siple Siple Coast West Antarctica |
geographic_facet |
Siple Siple Coast West Antarctica |
genre |
Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet The Cryosphere West Antarctica |
op_source |
The Cryosphere, Volume 11, Issue 4, Page 1913-1932 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/966 |
_version_ |
1782335098546290688 |