Projects per year
Abstract
This study uses data from six on-ice weather stations, calibrated MODIS-derived albedo and proglacial river gauging measurements to drive and validate an energy balance model. We aim to quantify the record-setting positive temperature anomaly in 2010 and its effect on mass balance and runoff from the Kangerlussuaq sector of the Greenland ice sheet. In 2010, the average temperature was 4.9 °C (2.7 standard deviations) above the 1974–2010 average in Kangerlussuaq. High temperatures were also observed over the ice sheet, with the magnitude of the positive anomaly increasing with altitude, particularly in August. Simultaneously, surface albedo was anomalously low in 2010, predominantly in the upper ablation zone. The low albedo was caused by high ablation, which in turn profited from high temperatures and low winter snowfall. Surface energy balance calculations show that the largest melt excess (∼170%) occurred in the upper ablation zone (above 1000 m), where higher temperatures and lower albedo contributed equally to the melt anomaly. At lower elevations the melt excess can be attributed to high atmospheric temperatures alone. In total, we calculate that 6.6 ± 1.0 km3 of surface meltwater ran off the ice sheet in the Kangerlussuaq catchment in 2010, exceeding the reference year 2009 (based on atmospheric temperature measurements) by ∼150%. During future warm episodes we can expect a melt response of at least the same magnitude, unless a larger wintertime snow accumulation delays and moderates the melt-albedo feedback. Due to the hypsometry of the ice sheet, yielding an increasing surface area with elevation, meltwater runoff will be further amplified by increases in melt forcings such as atmospheric heat.
Original language | English |
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Pages (from-to) | 199-209 |
Journal | Cryosphere |
Volume | 6 |
Issue number | 1 |
DOIs | |
Publication status | Published - 06 Sept 2012 |
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Dive into the research topics of 'Large surface meltwater discharge from the Kangerlussuaq sector of the Greenland ice sheet during the record-warm year 2010 explained by detailed energy balance observations'. Together they form a unique fingerprint.Projects
- 3 Finished
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Investigating Meltwater Flow Beneath the Greenland Ice Sheet using a Multi-tracer Approach
Hubbard, A. (PI)
Natural Environment Research Council
01 May 2011 → 30 Apr 2015
Project: Externally funded research
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A Holistic Model of Outlet Calving, Dynamic Acceloration and Drawdown for the Greenland Ice Sheet
Hubbard, A. (PI)
Natural Environment Research Council
01 Jun 2009 → 31 May 2011
Project: Externally funded research
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Dynamic Response of the Greenland Ice Sheet to Climate Forcing using a geophysical, Remote sensing and Numerical Modelling Framework
Hubbard, A. (PI)
Natural Environment Research Council
01 Mar 2009 → 31 Jan 2013
Project: Externally funded research