Greenland Ice Sheet flow response to runoff variability

We use observations of ice sheet surface motion from a Global Positioning System network operating from 2006 to 2014 around North Lake in west Greenland to investigate the dynamical response of the Greenland Ice Sheet's ablation area to interannual variability in surface melting. We find no sta...

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Main Authors: Stevens, Laura A., Behn, Mark D., Das, Sarah B., Joughin, Ian, Noël, Brice P. Y., van den Broeke, Michiel R., Herring, Thomas A
Other Authors: Woods Hole Oceanographic Institution
Format: Article
Language:en_US
Published: American Geophysical Union (AGU) 2019
Online Access:https://hdl.handle.net/1721.1/121545
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author Stevens, Laura A.
Behn, Mark D.
Das, Sarah B.
Joughin, Ian
Noël, Brice P. Y.
van den Broeke, Michiel R.
Herring, Thomas A
author2 Woods Hole Oceanographic Institution
author_facet Woods Hole Oceanographic Institution
Stevens, Laura A.
Behn, Mark D.
Das, Sarah B.
Joughin, Ian
Noël, Brice P. Y.
van den Broeke, Michiel R.
Herring, Thomas A
author_sort Stevens, Laura A.
collection MIT
description We use observations of ice sheet surface motion from a Global Positioning System network operating from 2006 to 2014 around North Lake in west Greenland to investigate the dynamical response of the Greenland Ice Sheet's ablation area to interannual variability in surface melting. We find no statistically significant relationship between runoff season characteristics and ice flow velocities within a given year or season. Over the 7 year time series, annual velocities at North Lake decrease at an average rate of −0.9 ± 1.1 m yr⁻², consistent with the negative trend in annual velocities observed in neighboring regions over recent decades. We find that net runoff integrated over several preceding years has a negative correlation with annual velocities, similar to findings from the two other available decadal records of ice velocity in western Greenland. However, we argue that this correlation is not necessarily evidence for a direct hydrologic mechanism acting on the timescale of multiple years but could be a statistical construct. Finally, we stress that neither the decadal slowdown trend nor the negative correlation between velocity and integrated runoff is predicted by current ice‐sheet models, underscoring that these models do not yet capture all the relevant feedbacks between runoff and ice dynamics needed to predict long‐term trends in ice sheet flow. Keywords: Greenland Ice Sheet; ice flow; runoff
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spelling mit-1721.1/1215452022-09-26T17:53:17Z Greenland Ice Sheet flow response to runoff variability Stevens, Laura A. Behn, Mark D. Das, Sarah B. Joughin, Ian Noël, Brice P. Y. van den Broeke, Michiel R. Herring, Thomas A Woods Hole Oceanographic Institution Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences thomas herring We use observations of ice sheet surface motion from a Global Positioning System network operating from 2006 to 2014 around North Lake in west Greenland to investigate the dynamical response of the Greenland Ice Sheet's ablation area to interannual variability in surface melting. We find no statistically significant relationship between runoff season characteristics and ice flow velocities within a given year or season. Over the 7 year time series, annual velocities at North Lake decrease at an average rate of −0.9 ± 1.1 m yr⁻², consistent with the negative trend in annual velocities observed in neighboring regions over recent decades. We find that net runoff integrated over several preceding years has a negative correlation with annual velocities, similar to findings from the two other available decadal records of ice velocity in western Greenland. However, we argue that this correlation is not necessarily evidence for a direct hydrologic mechanism acting on the timescale of multiple years but could be a statistical construct. Finally, we stress that neither the decadal slowdown trend nor the negative correlation between velocity and integrated runoff is predicted by current ice‐sheet models, underscoring that these models do not yet capture all the relevant feedbacks between runoff and ice dynamics needed to predict long‐term trends in ice sheet flow. Keywords: Greenland Ice Sheet; ice flow; runoff 2019-07-09T17:16:35Z 2019-07-09T17:16:35Z 2016-10 2016-09 Article http://purl.org/eprint/type/JournalArticle 0094-8276 https://hdl.handle.net/1721.1/121545 Stevens, Laura A. et al. “Greenland Ice Sheet Flow Response to Runoff Variability.” Geophysical Research Letters 43, 21 (November 2016): 11,295–11,303 © 2016 American Geophysical Union en_US http://dx.doi.org/10.1002/2016gl070414 Geophysical Research Letters Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Geophysical Union (AGU) Prof. Herring via Chris Sherratt
spellingShingle Stevens, Laura A.
Behn, Mark D.
Das, Sarah B.
Joughin, Ian
Noël, Brice P. Y.
van den Broeke, Michiel R.
Herring, Thomas A
Greenland Ice Sheet flow response to runoff variability
title Greenland Ice Sheet flow response to runoff variability
title_full Greenland Ice Sheet flow response to runoff variability
title_fullStr Greenland Ice Sheet flow response to runoff variability
title_full_unstemmed Greenland Ice Sheet flow response to runoff variability
title_short Greenland Ice Sheet flow response to runoff variability
title_sort greenland ice sheet flow response to runoff variability
url https://hdl.handle.net/1721.1/121545
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AT vandenbroekemichielr greenlandicesheetflowresponsetorunoffvariability
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