Articles | Volume 17, issue 12
https://doi.org/10.5194/tc-17-5075-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-17-5075-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
30 Nov 2023
Research article |
| 30 Nov 2023
| 30 Nov 2023
Observed and modeled moulin heads in the Pâkitsoq region of Greenland suggest subglacial channel network effects
Geosciences Department, University of Arkansas, Fayetteville, AR, USA
Centre for Hydrogeology and Geothermics, University of Neuchâtel, Neuchâtel, Switzerland
Kristin Poinar
Department of Geology and RENEW Institute, University at Buffalo, Buffalo, NY, USA
Lauren C. Andrews
Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD, USA
Matthew D. Covington
Geosciences Department, University of Arkansas, Fayetteville, AR, USA
Jessica Mejia
Department of Geology and RENEW Institute, University at Buffalo, Buffalo, NY, USA
Geosciences Department, University of South Florida, Tampa, FL, USA
Jason Gulley
Geosciences Department, University of South Florida, Tampa, FL, USA
Victoria Siegel
Sisu Field Solutions LLC, Austin, Texas, USA
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We introduce a model for moulin geometry motivated by the wide range of sizes and shapes of explored moulins. Moulins comprise 10–14 % of the Greenland englacial–subglacial hydrologic system and act as time-varying water storage reservoirs. Moulin geometry can vary approximately 10 % daily and over 100 % seasonally. Moulin shape modulates the efficiency of the subglacial system that controls ice flow and should thus be included in hydrologic models.
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We introduce a model for moulin geometry motivated by the wide range of sizes and shapes of explored moulins. Moulins comprise 10–14 % of the Greenland englacial–subglacial hydrologic system and act as time-varying water storage reservoirs. Moulin geometry can vary approximately 10 % daily and over 100 % seasonally. Moulin shape modulates the efficiency of the subglacial system that controls ice flow and should thus be included in hydrologic models.
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Short summary
Models simulating water pressure variations at the bottom of glaciers must use large storage parameters to produce realistic results. Whether that storage occurs englacially (in moulins) or subglacially is a matter of debate. Here, we directly simulate moulin volume to constrain the storage there. We find it is not enough. Instead, subglacial processes, including basal melt and input from upstream moulins, must be responsible for stabilizing these water pressure fluctuations.
Models simulating water pressure variations at the bottom of glaciers must use large storage...
