The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow
Ice velocities observed in 2005/06 at three GPS stations along the Sermeq Avannarleq flowline, West Greenland, are used to characterize an observed annual velocity cycle. We attempt to reproduce this annual ice velocity cycle using a 1-D ice-flow model with longitudinal stresses coupled to a 1-D hyd...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20140008938 2023-05-15T16:21:16+02:00 The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow Anderson, Robert S. Steffen, Konrad Phillips, Thomas Colgan, William Terence Rajaram, Harihar Zwally, H. Jay Abdalati, Waleed Unclassified, Unlimited, Publicly available February 15, 2012 application/pdf http://hdl.handle.net/2060/20140008938 unknown Document ID: 20140008938 http://hdl.handle.net/2060/20140008938 Copyright, Distribution as joint owner in the copyright CASI Geosciences (General) GSFC-E-DAA-TN9411 Journal Of Glaciology; 58; 207; 51-64 2012 ftnasantrs 2019-08-31T23:07:05Z Ice velocities observed in 2005/06 at three GPS stations along the Sermeq Avannarleq flowline, West Greenland, are used to characterize an observed annual velocity cycle. We attempt to reproduce this annual ice velocity cycle using a 1-D ice-flow model with longitudinal stresses coupled to a 1-D hydrology model that governs an empirical basal sliding rule. Seasonal basal sliding velocity is parameterized as a perturbation of prescribed winter sliding velocity that is proportional to the rate of change of glacier water storage. The coupled model reproduces the broad features of the annual basal sliding cycle observed along this flowline, namely a summer speed-up event followed by a fall slowdown event. We also evaluate the hypothesis that the observed annual velocity cycle is due to the annual calving cycle at the terminus. We demonstrate that the ice acceleration due to a catastrophic calving event takes an order of magnitude longer to reach CU/ETH ('Swiss') Camp (46km upstream of the terminus) than is observed. The seasonal acceleration observed at Swiss Camp is therefore unlikely to be the result of velocity perturbations propagated upstream via longitudinal coupling. Instead we interpret this velocity cycle to reflect the local history of glacier water balance. Other/Unknown Material glacier Greenland Ice Sheet NASA Technical Reports Server (NTRS) Greenland Avannarleq ENVELOPE(-49.100,-49.100,62.133,62.133) Sermeq Avannarleq ENVELOPE(-50.833,-50.833,71.033,71.033) |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
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Geosciences (General) |
spellingShingle |
Geosciences (General) Anderson, Robert S. Steffen, Konrad Phillips, Thomas Colgan, William Terence Rajaram, Harihar Zwally, H. Jay Abdalati, Waleed The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow |
topic_facet |
Geosciences (General) |
description |
Ice velocities observed in 2005/06 at three GPS stations along the Sermeq Avannarleq flowline, West Greenland, are used to characterize an observed annual velocity cycle. We attempt to reproduce this annual ice velocity cycle using a 1-D ice-flow model with longitudinal stresses coupled to a 1-D hydrology model that governs an empirical basal sliding rule. Seasonal basal sliding velocity is parameterized as a perturbation of prescribed winter sliding velocity that is proportional to the rate of change of glacier water storage. The coupled model reproduces the broad features of the annual basal sliding cycle observed along this flowline, namely a summer speed-up event followed by a fall slowdown event. We also evaluate the hypothesis that the observed annual velocity cycle is due to the annual calving cycle at the terminus. We demonstrate that the ice acceleration due to a catastrophic calving event takes an order of magnitude longer to reach CU/ETH ('Swiss') Camp (46km upstream of the terminus) than is observed. The seasonal acceleration observed at Swiss Camp is therefore unlikely to be the result of velocity perturbations propagated upstream via longitudinal coupling. Instead we interpret this velocity cycle to reflect the local history of glacier water balance. |
format |
Other/Unknown Material |
author |
Anderson, Robert S. Steffen, Konrad Phillips, Thomas Colgan, William Terence Rajaram, Harihar Zwally, H. Jay Abdalati, Waleed |
author_facet |
Anderson, Robert S. Steffen, Konrad Phillips, Thomas Colgan, William Terence Rajaram, Harihar Zwally, H. Jay Abdalati, Waleed |
author_sort |
Anderson, Robert S. |
title |
The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow |
title_short |
The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow |
title_full |
The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow |
title_fullStr |
The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow |
title_full_unstemmed |
The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow |
title_sort |
annual glaciohydrology cycle in the ablation zone of the greenland ice sheet: part 2. observed and modeled ice flow |
publishDate |
2012 |
url |
http://hdl.handle.net/2060/20140008938 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(-49.100,-49.100,62.133,62.133) ENVELOPE(-50.833,-50.833,71.033,71.033) |
geographic |
Greenland Avannarleq Sermeq Avannarleq |
geographic_facet |
Greenland Avannarleq Sermeq Avannarleq |
genre |
glacier Greenland Ice Sheet |
genre_facet |
glacier Greenland Ice Sheet |
op_source |
CASI |
op_relation |
Document ID: 20140008938 http://hdl.handle.net/2060/20140008938 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766009281241415680 |