Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model
In order to understand ice sheet response to climate change, it is critical to examine errors associated with ice flow model boundary conditions and forcing. It is also important to understand how these errors propagate through numerical ice sheet models and contribute to uncertainty in model output...
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | https://escholarship.org/uc/item/2cs580kg https://escholarship.org/content/qt2cs580kg/qt2cs580kg.pdf https://doi.org/10.1002/2014jf003359 |
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ftcdlib:oai:escholarship.org:ark:/13030/qt2cs580kg 2024-09-15T18:09:40+00:00 Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model Schlegel, N‐J Larour, E Seroussi, H Morlighem, M Box, JE 29 - 54 2015-01-01 application/pdf https://escholarship.org/uc/item/2cs580kg https://escholarship.org/content/qt2cs580kg/qt2cs580kg.pdf https://doi.org/10.1002/2014jf003359 unknown eScholarship, University of California qt2cs580kg https://escholarship.org/uc/item/2cs580kg https://escholarship.org/content/qt2cs580kg/qt2cs580kg.pdf doi:10.1002/2014jf003359 CC-BY Journal of Geophysical Research Earth Surface, vol 120, iss 1 Climate Action uncertainty ice stream ice flow mass flux ice discharge Earth Sciences article 2015 ftcdlib https://doi.org/10.1002/2014jf003359 2024-06-28T06:28:20Z In order to understand ice sheet response to climate change, it is critical to examine errors associated with ice flow model boundary conditions and forcing. It is also important to understand how these errors propagate through numerical ice sheet models and contribute to uncertainty in model output. Using established uncertainty quantification methods within the Ice Sheet System Model (ISSM), we investigate the sensitivity of ice flow within the Northeast Greenland Ice Stream (NEGIS) to key fields, including ice viscosity and basal drag, and compare them with model sensitivity to climate forcing. In addition, we examine how errors in model input manifest as mass flux uncertainties during a forward simulation of the NEGIS from 1989 to 2010. Overall, we find that mass flux is most uncertain in the main outlets, Nioghalvfjerdsbræ and Zachariæ Isstrøm, and that mass flux is most sensitive to basal drag, though errors associated with basal drag are poorly constrained and difficult to quantify. Given our knowledge of errors associated with the thermal properties of ice, we estimate that in the ablation area, the effects of cryohydrologic warming contribute over 4 times more mass flux uncertainty that do errors in geothermal heat flux. We find that NEGIS total ice discharge is associated with a 0.7 Gt/yr (2.6%) uncertainty due to errors in geothermal heat flux and a 3.3 Gt/yr (11.6%) uncertainty due to the added effects of cryohydrologic warming. In comparison, errors in surface mass balance contribute 4.5 Gt/yr to NEGIS total discharge uncertainty. Key Points Mass flux is most sensitive to basal drag Mass flux is the most uncertain at the 79North outlet Geothermal heat flux uncertainty is less than that from cryohydrologic warming. Article in Journal/Newspaper Greenland Ice Sheet University of California: eScholarship Journal of Geophysical Research: Earth Surface 120 1 29 54 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Climate Action uncertainty ice stream ice flow mass flux ice discharge Earth Sciences |
spellingShingle |
Climate Action uncertainty ice stream ice flow mass flux ice discharge Earth Sciences Schlegel, N‐J Larour, E Seroussi, H Morlighem, M Box, JE Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model |
topic_facet |
Climate Action uncertainty ice stream ice flow mass flux ice discharge Earth Sciences |
description |
In order to understand ice sheet response to climate change, it is critical to examine errors associated with ice flow model boundary conditions and forcing. It is also important to understand how these errors propagate through numerical ice sheet models and contribute to uncertainty in model output. Using established uncertainty quantification methods within the Ice Sheet System Model (ISSM), we investigate the sensitivity of ice flow within the Northeast Greenland Ice Stream (NEGIS) to key fields, including ice viscosity and basal drag, and compare them with model sensitivity to climate forcing. In addition, we examine how errors in model input manifest as mass flux uncertainties during a forward simulation of the NEGIS from 1989 to 2010. Overall, we find that mass flux is most uncertain in the main outlets, Nioghalvfjerdsbræ and Zachariæ Isstrøm, and that mass flux is most sensitive to basal drag, though errors associated with basal drag are poorly constrained and difficult to quantify. Given our knowledge of errors associated with the thermal properties of ice, we estimate that in the ablation area, the effects of cryohydrologic warming contribute over 4 times more mass flux uncertainty that do errors in geothermal heat flux. We find that NEGIS total ice discharge is associated with a 0.7 Gt/yr (2.6%) uncertainty due to errors in geothermal heat flux and a 3.3 Gt/yr (11.6%) uncertainty due to the added effects of cryohydrologic warming. In comparison, errors in surface mass balance contribute 4.5 Gt/yr to NEGIS total discharge uncertainty. Key Points Mass flux is most sensitive to basal drag Mass flux is the most uncertain at the 79North outlet Geothermal heat flux uncertainty is less than that from cryohydrologic warming. |
format |
Article in Journal/Newspaper |
author |
Schlegel, N‐J Larour, E Seroussi, H Morlighem, M Box, JE |
author_facet |
Schlegel, N‐J Larour, E Seroussi, H Morlighem, M Box, JE |
author_sort |
Schlegel, N‐J |
title |
Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model |
title_short |
Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model |
title_full |
Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model |
title_fullStr |
Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model |
title_full_unstemmed |
Ice discharge uncertainties in Northeast Greenland from boundary conditions and climate forcing of an ice flow model |
title_sort |
ice discharge uncertainties in northeast greenland from boundary conditions and climate forcing of an ice flow model |
publisher |
eScholarship, University of California |
publishDate |
2015 |
url |
https://escholarship.org/uc/item/2cs580kg https://escholarship.org/content/qt2cs580kg/qt2cs580kg.pdf https://doi.org/10.1002/2014jf003359 |
op_coverage |
29 - 54 |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
Journal of Geophysical Research Earth Surface, vol 120, iss 1 |
op_relation |
qt2cs580kg https://escholarship.org/uc/item/2cs580kg https://escholarship.org/content/qt2cs580kg/qt2cs580kg.pdf doi:10.1002/2014jf003359 |
op_rights |
CC-BY |
op_doi |
https://doi.org/10.1002/2014jf003359 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
120 |
container_issue |
1 |
container_start_page |
29 |
op_container_end_page |
54 |
_version_ |
1810447246193328128 |