| 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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M.P. Bhatia, S.B. Das, E.B. Kujawinski, P. Henderson, A. Burke, and M.A.Charette, Seasonal evolution of water contributions to discharge from a Greenland outlet glacier: Insight from a new isotope-mixing model, J. Glaciology, v.57(205), 929-941, 2011
The Greenland ice sheet (GrIS) subglacial hydrological system may undergo a seasonal evolution, with significant geophysical and biogeochemical implications. We present results from a new isotope mixing model to quantify the relative contributions of surface snow, glacial ice, and delayed flow to the bulk meltwater discharge from a small (~5-km2) land-terminating GrIS outlet glacier during melt onset (May) and at peak melt (July). We use radioactive (radon-222) and stable isotopes (oxygen-18, deuterium) to differentiate the source-water contributions. Atmospherically-derived beryllium-7 further constrains meltwater transit time from the glacier surface to the ice margin. We show that (i) radon-222 is a promising tracer for glacial waters stored at the bed and (ii) a quantitative chemical mixing model can be constructed by combining radon-222 and the stable water isotopes. Applying this model to the bulk subglacial outflow from our study area, we find a constant delayed flow (stored) component from melt onset through peak melt. This component is diluted first by snow-melt and then by increasing glacial ice-melt as the season progresses. Results from this pilot study are consistent with the hypothesis that subglacial drainage beneath land-terminating sections of the GrIS undergoes a seasonal evolution from a distributed system to a channelized one.
FILE » Bhatiaetal2011.pdf
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