Geophysical Research Letters, 36, L01501; doi:10.1029/2008GL035758.
Greenland ice sheet motion coupled with daily melting in late summer
Andrew Shepherd (School of Geosciences, University of Edinburgh, Edinburgh, UK), Alun Hubbard (Institute of Geography and Earth Sciences, University of Aberystwyth, Aberystwyth, UK), Peter Nienow (School of Geosciences, University of Edinburgh, Edinburgh, UK), Matt King (School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, UK), Malcolm McMillan (School of Geosciences, University of Edinburgh, Edinburgh, UK), and Ian Joughin (Polar Science Center, Applied Physics Lab, University of Washington, Seattle, WA, USA)
Abstract
We use ground-based and satellite observations to detect large diurnal and longer-period variations in the flow of the Greenland Ice Sheet (GrIS) during late summer that are strongly coupled with changes in its surface hydrology. The diurnal signals are associated with periodic changes in surface melting, and the longer-period signals are associated with the episodic drainage of supra-glacial lakes. Ice velocity doubles around 2 h after peak daily melting and returns approximately to wintertime levels around 12 h afterwards, demonstrating an intimate link between the surface and basal hydrology. During late summer, the ice sheet accelerates by 35% per positive degree-day of melting. The observed link between surface melting and enhanced flow is typical of Alpine glaciers, which may provide an appropriate analogue for the evolution of the GrIS in a warming climate.
(Received 20 August 2008, accepted 4 November 2008, published 7 January 2009.)
Citation: (2009), Greenland ice sheet motion coupled with daily melting in late summer, Geophys. Res. Lett., 36, L01501, doi:10.1029/2008GL035758.
Link to abstract: http://www.agu.org/pubs/crossref/2009/2008GL035758.shtml
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