| Publications | | » | Tropical Pacific influence on W. Antarctic marine aerosols, 2013 submitted
 | | » | Thwaites Glacier, Antarctica accumulation, 2013 submitted
| | » | Influence of supraglacial lakes on seasonal ice flow, TCD, in review, 2013
| | » | Greenland Iron Export, Nature Geosc, 2013
| | » | Greenland Organic Carbon Export, GCA, 2013
| | » | Amundsen Coast Sea Ice and Polynya Variability, JGR, 2013
| | » | Ice Core 10Be Records, EPSL, 2012
| | » | Antarctic Ice Sheet Surface Melting, JGR, 2012
| | » | Greenland discharge isotope mixing model, J. Glac., 2011
| | » | Future Science Opportunities in Antarctica and the Southern Ocean, NRC Report, 2011
| | » | Greenland Ice Sheet DOM, GCA, 2010
| | » | Ice Sheet Hydrofracture and Water-transport Model, GRL, 2009
| | » | Greenland Supraglacial Lake Drainage, Science, 2008
| | » | Greenland Seasonal Speedup, Science, 2008
| | » | West Antarctica Holocene Climate, JGR, 2008
| | » | Greenland Accumulation, J. Climate, 2006
| | » | Melt Layer Formation, J. Glac, 2005
| | » | Whillans Ice Stream Deceleration, GRL, 2005
| | » | Siple Dome Temperature Variability, Annals Glac., 2002
| | » | Patagonian Icefield SAR, JGR, 1996
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I. Joughin, S.B. Das, G.E. Flowers, M.D. Behn, R.B. Alley, M.A. King, B.E. Smith, J. Bamber, M.R. van den Broeke, J.H. van Angelen , Influence of supraglacial lakes and ice-sheet geometry on seasonal ice-flow velocitiy, The Cryosphere Discuss, in review
Summer surface meltwater descends through hundreds of meters of glacial ice to lubricate the base of the Greenland Ice Sheet, seasonally enhancing ice flow. While this enhancement does not account for recent large increases in mean-annual ice-flow speed, it may become more important in controlling Greenland’s contribution to sea-level in the coming decades to centuries as marine-terminating outlet glaciers retreat from their deep troughs. Here we use new surface velocity observations to examine the influence of supraglacial lake drainages and surface melt rate on ice flow. We find large, spatially extensive speedups concurrent with times of lake drainage, showing that lakes play a key role in modulating regional ice flow. While surface meltwater is supplied to the bed via a geographically sparse network of moulins, the observed ice-flow enhancement suggests that this meltwater spreads widely over the ice-sheet bed. We find that the complex spatial pattern of speedup is strongly determined by the combined influence of bed and surface topography on subglacial water flow. Thus, modeling of ice-sheet basal hydrology likely will require knowledge of bed topography resolved at scales (sub-kilometer) far finer than existing data (several km).
Influence of supraglacial lakes and ice-sheet geometry on seasonal ice-flow variability |
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