A continuum model for meltwater flow through compacting snow
Meltwater is produced on the surface of glaciers and ice sheets when the seasonal energy forcing warms the snow to its melting temperature. This meltwater percolates into the snow and subsequently runs off laterally in streams, is stored as liquid water, or refreezes, thus warming the subsurface...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-12-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/11/2799/2017/tc-11-2799-2017.pdf |
| Summary: | Meltwater is produced on the surface of glaciers and ice sheets when the
seasonal energy forcing warms the snow to its melting temperature. This
meltwater percolates into the snow and subsequently runs off laterally
in streams, is stored as liquid water, or refreezes, thus warming the
subsurface through the release of latent heat. We present a continuum model
for the percolation process that includes heat conduction, meltwater
percolation and refreezing, as well as mechanical compaction. The model is
forced by surface mass and energy balances, and the percolation process is
described using Darcy's law, allowing for both partially and fully saturated
pore space. Water is allowed to run off from the surface if the snow is fully
saturated. The model outputs include the temperature, density, and
water-content profiles and the surface runoff and water storage. We
compare the propagation of freezing fronts that occur in the model to
observations from the Greenland Ice Sheet. We show that the model applies to
both accumulation and ablation areas and allows for a transition between the
two as the surface energy forcing varies. The largest average firn
temperatures occur at intermediate values of the surface forcing when
perennial water storage is predicted. |
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| ISSN: | 1994-0416 1994-0424 |