The effect of the north-east ice stream on the Greenland ice sheet in changing climates
International audience The north-east Greenland ice stream (NEGIS) was discovered as a large fast-flow feature of the Greenland ice sheet by synthetic aperture radar (SAR) imaginary of the ERS-1 satellite. In this study, the NEGIS is implemented in the dynamic/thermodynamic, large-scale ice-sheet mo...
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ftccsdartic:oai:HAL:hal-00298522v1 2023-11-12T04:16:33+01:00 The effect of the north-east ice stream on the Greenland ice sheet in changing climates Greve, R. Otsu, S. Institute of Low Temperature Science Sapporo Hokkaido University Sapporo, Japan Graduate School of Environmental Science 2007-06-20 https://hal.science/hal-00298522 https://hal.science/hal-00298522/document https://hal.science/hal-00298522/file/tcd-1-41-2007.pdf en eng HAL CCSD Copernicus hal-00298522 https://hal.science/hal-00298522 https://hal.science/hal-00298522/document https://hal.science/hal-00298522/file/tcd-1-41-2007.pdf info:eu-repo/semantics/OpenAccess ISSN: 1994-0432 EISSN: 1994-0440 The Cryosphere Discussions https://hal.science/hal-00298522 The Cryosphere Discussions, 2007, 1 (1), pp.41-76 [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2007 ftccsdartic 2023-10-21T23:15:03Z International audience The north-east Greenland ice stream (NEGIS) was discovered as a large fast-flow feature of the Greenland ice sheet by synthetic aperture radar (SAR) imaginary of the ERS-1 satellite. In this study, the NEGIS is implemented in the dynamic/thermodynamic, large-scale ice-sheet model SICOPOLIS (Simulation Code for POLythermal Ice Sheets). In the first step, we simulate the evolution of the ice sheet on a 10-km grid for the period from 250 ka ago until today, driven by a climatology reconstructed from a combination of present-day observations and GCM results for the past. We assume that the NEGIS area is characterized by enhanced basal sliding compared to the "normal", slowly-flowing areas of the ice sheet, and find that the misfit between simulated and observed ice thicknesses and surface velocities is minimized for a sliding enhancement by the factor three. In the second step, the consequences of the NEGIS, and also of surface-meltwater-induced acceleration of basal sliding, for the possible decay of the Greenland ice sheet in future warming climates are investigated. It is demonstrated that the ice sheet is generally very susceptible to global warming on time-scales of centuries and that surface-meltwater-induced acceleration of basal sliding can speed up the decay significantly, whereas the NEGIS is not likely to dynamically destabilize the ice sheet as a whole. Article in Journal/Newspaper East Greenland Greenland Ice Sheet The Cryosphere The Cryosphere Discussions Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Greve, R. Otsu, S. The effect of the north-east ice stream on the Greenland ice sheet in changing climates |
topic_facet |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The north-east Greenland ice stream (NEGIS) was discovered as a large fast-flow feature of the Greenland ice sheet by synthetic aperture radar (SAR) imaginary of the ERS-1 satellite. In this study, the NEGIS is implemented in the dynamic/thermodynamic, large-scale ice-sheet model SICOPOLIS (Simulation Code for POLythermal Ice Sheets). In the first step, we simulate the evolution of the ice sheet on a 10-km grid for the period from 250 ka ago until today, driven by a climatology reconstructed from a combination of present-day observations and GCM results for the past. We assume that the NEGIS area is characterized by enhanced basal sliding compared to the "normal", slowly-flowing areas of the ice sheet, and find that the misfit between simulated and observed ice thicknesses and surface velocities is minimized for a sliding enhancement by the factor three. In the second step, the consequences of the NEGIS, and also of surface-meltwater-induced acceleration of basal sliding, for the possible decay of the Greenland ice sheet in future warming climates are investigated. It is demonstrated that the ice sheet is generally very susceptible to global warming on time-scales of centuries and that surface-meltwater-induced acceleration of basal sliding can speed up the decay significantly, whereas the NEGIS is not likely to dynamically destabilize the ice sheet as a whole. |
author2 |
Institute of Low Temperature Science Sapporo Hokkaido University Sapporo, Japan Graduate School of Environmental Science |
format |
Article in Journal/Newspaper |
author |
Greve, R. Otsu, S. |
author_facet |
Greve, R. Otsu, S. |
author_sort |
Greve, R. |
title |
The effect of the north-east ice stream on the Greenland ice sheet in changing climates |
title_short |
The effect of the north-east ice stream on the Greenland ice sheet in changing climates |
title_full |
The effect of the north-east ice stream on the Greenland ice sheet in changing climates |
title_fullStr |
The effect of the north-east ice stream on the Greenland ice sheet in changing climates |
title_full_unstemmed |
The effect of the north-east ice stream on the Greenland ice sheet in changing climates |
title_sort |
effect of the north-east ice stream on the greenland ice sheet in changing climates |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://hal.science/hal-00298522 https://hal.science/hal-00298522/document https://hal.science/hal-00298522/file/tcd-1-41-2007.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland Ice Sheet The Cryosphere The Cryosphere Discussions |
genre_facet |
East Greenland Greenland Ice Sheet The Cryosphere The Cryosphere Discussions |
op_source |
ISSN: 1994-0432 EISSN: 1994-0440 The Cryosphere Discussions https://hal.science/hal-00298522 The Cryosphere Discussions, 2007, 1 (1), pp.41-76 |
op_relation |
hal-00298522 https://hal.science/hal-00298522 https://hal.science/hal-00298522/document https://hal.science/hal-00298522/file/tcd-1-41-2007.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782333601267843072 |