EGU21-1099
https://doi.org/10.5194/egusphere-egu21-1099
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

The meltwater feedbacks on ice dynamics, influence of melt amplitude, duration and extent.

Basile de Fleurian1, Petra M. Langebroeke2, and Richard Davy3
Basile de Fleurian et al.
  • 1UiB and Bjerknes centre, Center for Climate Research, Bergen, Norway (basile.defleurian@uib.no)
  • 2NORCE and Bjerknes Centre for Climate Research, Bergen, Norway
  • 3NERSC and Bjerknes Centre for Climate Research, Bergen, Norway

In recent years, temperatures over the Greenland ice sheet have been rising, leading to an increase in surface melt. This increase however can not be reduced to a simple number. Throughout the recent years we have seen some extreme melt seasons with melt extending over the whole surface of the ice sheet (2012) or melt seasons of lower amplitudes but with a longer duration (2010). The effect of those variations on the subglacial system and hence on ice dynamic are poorly understood and are still mainly deduced from studies based on mountain glaciers.

Here we apply the Ice-sheet and Sea-level System Model (ISSM) to a synthetic glacier with a geometry similar to a Greenland ice sheet land terminating glacier. The forcing is designed such that it allows to investigate different characteristics of the melt season: its length, intensity or the spatial extension of the melt. Subglacial hydrology and ice dynamics are coupled within ISSM is coupled to a subglacial hydrology model, allowing to study the response of the system in terms of subglacial water pressure and the final impact on ice dynamics. Of particular interest is the evolution of the distribution of the efficient and inefficient component of the subglacial drainage system which directly impacts the water pressure evolution at the base of the glacier.

We note that the initiation of the melt season and the intensity of the melt at this period is a crucial parameter when studying the dynamic response of the glacier to different melt season characteristics. From those results, we can infer a more precise evolution of the dynamics of land terminating glaciers that are heavily driven by their subglacial drainage system. We also highlight which changes in the melt season pattern would be the most damageable for glacier stability in the future.

How to cite: de Fleurian, B., Langebroeke, P. M., and Davy, R.: The meltwater feedbacks on ice dynamics, influence of melt amplitude, duration and extent., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1099, https://doi.org/10.5194/egusphere-egu21-1099, 2021.

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